This is my final assignment! It's from the PP2 module - where I take some CPD related to my profession. I picked Blockchain. Because I hate myself.

I've blogged about the course itself. The middle two parts of this paper are about that - why I chose it and how I put it into practice. The first and fourth parts are, as far as I can tell, unrelated. We have to write about reflection in the workplace. I am not very introspective, and I don't really enjoy it. So I found as many papers as I could to dispute the premise. The final part was about a modern issue of interest to professionals - which at least had the advantage of being interesting.

I was overjoyed with a mark of 81% (in the English system 50% is a pass, 60% is a commendation, 70% is distinction). That takes my on-course average to a shade over 71%. I wonder if I can keep that up for the final project?

I used my algorithm to write an assignment to complete this.

A few disclaimers:

• I don't claim it to be brilliant. I am not very good at academic-style writing.
• It is fairly inaccurate. Many of the concepts on reflection were not relevant to my workplace, so there is a lot of fudging.
• This isn't how I'd write a normal document for work - and the facts have not been independently verified.
• This isn't the policy of my employer, nor does it represent their opinions. It has only been assessed from an academic point of view.
• It has not been peer reviewed, nor are the data guaranteed to be an accurate reflection of reality. Cite at your own peril.
• I've quickly converted this from Google Docs + Zotero into MarkDown. Who knows what weird formatting that'll introduce!
• All references are clickable - going straight to the source. Reference list is at the end, most links converted using DOI2HT.ML.

And, once more, this is not official policy. It was not commissioned by anyone. It is an academic exercise. Adjust your expectations accordingly.

1. A critical review of three reflective models and selection of one of these to use to support your reflection in the assignment

1.1 Review of 3 models

The author has reviewed the assigned literature and beyond in order to compare multiple models of reflection. Three models are evaluated by the author in Table 1.

Ideally, reflection would allow professionals to pair with more experienced practitioners and compare the effectiveness of their learning (Oluwatoyin, 2015). In the author's experience, it is not the model which is important - but rather working in a team to understand how to learn and how others learn.

Table 1	ERA Cycle (Jasper, 2013)	Double Loop Learning (Argyris, 1977)	DIEP (Rogers, 2001)
Model
Strengths	Simple model.	Part of many Agile processes (Richardson, 2014). Suitable for business processes.	Structured model. Suitable for teams and individuals.
Weaknesses	Content free. Offers no structure to the reflection.	Not a "silver bullet" (Crossan, 2003). Risk of undermining corporate objectives (Soeters, 2022).	Not universally applicable. No feedback loop.

1.2 Evaluation of the effectiveness of the chosen module based on PP1

The author chose the DIEP reflective model for PP1 but did not find it as effective as hoped. Having extensively reviewed the literature, the author found strong evidence of the widespread use of reflective practice in healthcare (Norrie et al., 2012) but little convincing evidence that reflection is effective in digital organisations (Dors et al., 2020).

Additionally, evidence shows reflective practice rarely leads to altered behaviours (Granan, 2016). In two decades of work experience, the author has found specific models of reflection tend not to be the cause of improvements. Instead, modern digital employees are better served by concentrating on the act of reflecting as a team (Jha and Vazirani, 2021).

Others have concluded that reflection is "a contemporary label for an aspect of human thinking processes whose popularity has exceeded its conceptual and theoretical grasp" (Kompf and Bond, 1995) - although this is disputed by those who think these obstacles can be overcome (Denton, 2011). Many researchers think forcing reflection on learners is "futile" due to their desire to be seen as competent (McGarr and Ó Gallchóir, 2020) and the institutional disincentives to be honest (Hobbs, 2007). Others recognise that although isolated reflection is an "ambiguous moral exercise" (Hargreaves, 2004) it may be useful in a "safe and supportive environment" (Fernsten and Fernsten, 2005).

1.3 Comparisons with other models

In the author's opinion, there is little to distinguish between any of the popular reflective models. They only differ in the amount of administrative steps each theorist is willing to dedicate to "navel-gazing" (Andresen and Emerson, 1991).

As noted by Smith & Martin, most professionals in the author's field introduced to reflective practice do not continue with it when given a free choice (Smith and Martin, 2014). This failure to adopt reflection is present in many workplaces (Eaton, 2016). Furthermore, there is evidence showing forced reflective practice may be detrimental to the practitioner's development in the modern workplace (Hargreaves, 2004). Again, this is found across various types of profession (Wong, Whitcombe and Boniface, 2016).

While reflective practice is well accepted in fields like medicine (Ooi, Fisher and Coker, 2021), the author agrees with the critics who argue that there is a "marked dearth of evidence that reflective practice techniques yield more reflective practitioners" (Lilienfeld and Basterfield, 2020).

1.4 The relevance of the chosen model to the context of PP2

Due to the ever-changing nature of work, the modern employee must be prepared for lifelong learning. Reflecting on the learning process and achievements is thought to be critical to future employability (Helyer, 2015). However, the use of reflection has uncertain effectiveness (Mann, Gordon and MacLeod, 2009) and many novice practitioners find the application of reflection to be daunting (Walker et al., 2013).

There is a "theory practice gap" identified by Schön (Schön, 1987) - whereby practitioners aren't able to effectively utilise reflection despite repeated exposure to theoretical concepts. Therefore, the author has chosen to use DIEP as it is a familiar model which can be quickly iterated to uncover new ways of reflecting. The author's current working environment expects all processes to be rapidly iterative.

2. A discussion of the selection of CPD in relation to the wider technical area, the context within your organisation, and my specific role

2.1 Description

I chose a course which was designed to upskill me in an interesting new technology - Blockchain. It covered the basics of the technology and its applications.

Early Blockchain proponents said that "the digital revolution challenges us to develop new institutions in a much shorter period of time" (Szabo, 1997). As a new member of a team inside a newly formed institution, I wanted to see if Blockchain could help deliver rapid change. This fits with my organisation's recently published business objectives (Cabinet Office, 2021).

2.2 Relevance

There are various embryonic Blockchain projects within my organisation. For example the Royal Mint is planning a series of Non-Fungible Tokens (Sparkes, 2022) and legislators are interested in the possibilities of Blockchain voting (Holmes, 2022).

As this is a relatively new field, the Civil Service finds itself with a lack of expertise in this technology. With intense scrutiny from media, industry, and academia, I felt it was important to increase my knowledge in this area. Given the interest from senior stakeholders, I need to be able to swiftly and accurately evaluate future projects. As part of my organisation's 2025 roadmap, they have committed to exploring this technology (Wheeler, 2022), so it is of high relevance to my job.

2.3 Context

Our team deals with the security of critical national infrastructure - specifically, the integrity of the .gov.uk domain name ecosystem.

There are multiple parties with interest in this system, all with varying levels of trust in each other, which makes distributed technology particularly pertinent. There are also novel social, ethical, and legal implications which I wanted to explore, e.g. whether the immutability of Blockchain is compatible with our data protection obligations under GDPR. I also had to consider the ethical implications of endorsing a technology with a disastrous effect on climate change (Onat et al., 2021).

Finally, there are mixed views of Blockchain technologies, and many associate it primarily with scams (Phan, Li and Mentzer, 2019). I wanted to see if these issues would be a barrier to adoption.

2.4 Author's Role

I am a noted sceptic of Blockchain technology (Ross, Cretu and Lemieux, 2021) and wanted to provide more rigour to my analyses.

As part of my Personal Development Plan, I am looking for new technologies which will enhance my skills, reputation, and employability. With a predicted surge in Blockchain roles (Ge et al., 2021), I thought this CPD would help increase my employability and allow me to bring new skills to my employers.

2.5 Possible Alternatives

In conjunction with my team, I investigated other courses which may have been suitable. As indicated in my PDP, I have an identified learning need to acquire more practical knowledge of the fundamentals of DNS infrastructure. On-the-job training was thought to be a better route to learning these skills because they rely heavily on practical application rather than theoretical understanding. Some of the "soft skills" which I need to develop were not available as directed CPD. Finally, I investigated whether a series of video lectures on Blockchain would be acceptable (Gensler, 2018) - but they were unaccredited.

2.6 Evaluation

On reflection, I found this to be an extremely disappointing course. Although it taught me the key algorithms and history of the technology, the set text book was poorly written, with multiple factual and grammatical mistakes. Large parts of the book were plagiarised from other books and websites (Bavisi, 2021).

After discussing the course content with my peers, it became clear to me how much of the information was presented uncritically and without evidence. The course was provided by an organisation with a self-professed history of chauvinism and misogyny (Dallaway, 2021). While there were some interesting technical elements in the text, there was a lack of academic rigour which led to questionable conclusions.

3. An overview of how the CPD has been applied within my professional practice

3.1 An overview of the CPD

The course was a self-directed course designed to give an overview of various Blockchain technologies. It provided several case studies describing where this technology has been found useful, and mistakes which have been made with it.

It also discussed the basics of the Solidity programming language and how it can be used to implement "smart contracts". There was some investigation of environmental impacts, and which industries are ripe for disruption.

There was very little critical reflection on the flaws of the technology, and only a brief mention of the fraud it has facilitated (Trozze et al., 2022).

I learned the theories behind Blockchain, the programming languages used to construct Smart Contracts, and several practical use-cases.

3.2 Identification of specific projects for which this CPD has had an impact

My starting point was the flowchart created by the National Institute of Standards and Technology (NIST) - see Figure 01.

Using this tool, I identified a project requiring shared data, which were immutable and didn't contain sensitive data, contributed by multiple parties, and where no single entity could be in control, resulting in a tamper-proof log of data. An engagement exercise was carried out with stakeholders to see if there was sufficient interest to create a proof-of-concept.

Figure 01 - Flowchart from NISTIR 8202 The flowchart presented in NISTIR 8202 demonstrates reasons to adopt Blockchain (Yaga et al., 2018)

The background to the issue faced derives from the complicated constitution of the United Kingdom. The UK is often described as a country of four nations (Adenuga and Ogunduyile, 2020), so our service encompasses the top-level domains of .uk, .wales / .cymru, and .scot (note, there is no TLD for N. Ireland (Webster, 2019)).

There are also TLDs for Crown Dependencies and Overseas Territories, which are outside our purview. Of academic interest is the .gb TLD which represents Great Britain, but is all but abandoned (Martins dos Santos and Anastácio, 2022).

The multi-stakeholder group is complex; including separate legal and regulatory frameworks in each jurisdiction, various devolved competencies, and independence of operation which is both de facto and de jure. This is the perfect environment to see whether a "trustless" technology like Blockchain can thrive when applied to the seemingly anodyne task of collating DNS records.

Therefore, the CPD was applied to a project investigating the feasibility of using a permissioned blockchain to record DNS changes to critical domains.

3.3 Discussion and evidence of technical knowledge acquired in relation to the targeted apprenticeship standard.

A proof-of-concept model was created based around the concept of a Private blockchain.

A Private chain allows trusted participants to maintain a shared ledger i.e. it is not open to the public. This means it is quicker to iterate architectural design choices once all participants have agreed to them. It also requires less security against malicious nodes in the network. I learned that there are some disadvantages - because of the small number of participants it is hard to defend against multiple malicious nodes.

There are multiple ways to generate consensus in Blockchains. The course taught me that "Proof of Work" is the predominant method in public chains, but there are several more suitable consensus algorithms for Private Chains (Pahlajani, Kshirsagar and Pachghare, 2019).

Given the specific and limited number of participants, I decided to investigate voting consensus. This allows a pre-agreed quorum of voters to sign transactions to mark them as valid.

Any database - whether traditional or decentralised - needs to be designed for future requirements. While the proponents of Blockchain highlight the disparate nature of nodes as being essential for performance, I learned from a closer reading of the literature that there are several complex scaling issues related to how a Blockchain grows (Croman et al., 2016).

My investigation found that a Distributed Ledger would face two main scaling challenges. Firstly, the time taken to add records would slow down with every insertion operation due to the need to revalidate the entire chain. Secondly, consensus seeking algorithms introduce latency depending on the responsiveness of other nodes. Both of these are problematic for services which need rapid updates.

An interesting and innovative feature of some Blockchains are so-called "smart contracts" (Schuster, 2021). These can be thought of as stored procedures - code which exists on the chain and is executed by nodes under specified circumstances. For example, a smart contract could execute a transaction (writing data to the chain) when the chain reaches a specific state. In this paradigm, nodes will automatically run the code contained in the contract when all participants meet certain conditions.

Despite their name, there is little about smart contracts which would make a valid agreement under existing UK contract law (Rühl, 2021). As has been recently demonstrated, contracts created by programmers may have significant logical flaws which may lead to devastating financial consequences. These bugs cannot necessarily be detected with analysis tools (Ghaleb and Pattabiraman, 2020).

One repeated concern expressed by stakeholders was the inability for Blockchains to redact or remove incorrect data. Colleagues in HM Land Registry published a "lessons learned" retrospective which investigated the inherent problems they found with immutable data structures (Tombs, 2019). GDPR requires our organisation to correct any mistakes about our data subjects. Because of the immutability of the blockchain structure, it is impossible to remove or alter data while preserving the chain's integrity. This represents a fundamental contradiction - and sets up a dilemma which may not be resolvable (Tatar, Gokce and Nussbaum, 2020).

The skills I learned on this CPD enabled me to understand what Blockchain technology purports to deliver and - more importantly - comprehend its limitations and defects. I was able to create a research plan to meet the user needs of our stakeholders.

On presentation of the proposals, there was considerable - and justified - scepticism from all parties involved in this exercise. Some had little interest in the technology, and several were already convinced that this was a "solution in search of a problem". Another had recently lost a considerable amount of money on cryptocurrencies and was convinced all Blockchain-based projects were a scam.

In conclusion, there was little interest in progressing the solution once we had reflected on the limitations of Blockchain technology. Despite the high interest by Governments in Blockchain technology (OECD, 2018) my research has concluded they are technologically deficient. A more practical solution may be a Merkle Tree variant as implemented in Google's Certificate Transparency Logs (Laurie, 2014).

3.4 Reflections and commentary on the next stages of my professional development

I will reflect on the application of the CPD using the DIEP model (Rogers, 2001) as discussed in §1.4.

Describe

I investigated whether Blockchain could be effectively integrated into a multi-party DNS agreement. I undertook a complex investigation consisting of analysis, literature review, stakeholder discussion, and understanding of key algorithms. This formed a testable hypothesis to see if it could meet business needs. It could not.

Interpret

I am grateful that my workplace embraces a culture of "Fail Fast" (Ehrenberg and King, 2020). Being able to experiment in an environment with high psychological safety and no fear of ridicule was an empowering experience. Even though the experiment failed, it taught me about the storage solutions and information governance issues present in Blockchain.

Evaluate effectiveness

Although Blockchain presents some potentially interesting data structures and solutions to esoteric cryptography problems, there is little practical application yet. Through this experience, I learned how to identify scams and become aware of how zealots attempt to convert the unwary into their "digital ponzi schemes" (Scharfman, 2022). I also gained an appreciation for the way novel technologies get assessed within my organisation.

Plan for the future

While it is important to explore the frontiers of innovation and explore idea space for emergent concepts, there is a risk that over-hyped technology will quickly fall out of fashion once its deficiencies are well understood. Therefore, to protect my own credibility, the next stage of my professional development will need to be in a more practical direction.

4. A discussion of a contemporary challenge

4.1 A Contemporary Challenge

Digital exclusion from government services is a pressing issue for society. Lack of reliable and digital identity often means vulnerable users in the UK are unable to access vital online services (Crosby, 2008). Internationally, the World Bank estimates 1.1 billion people have no proof of identity (Rajendran, 2017).

The UK's approach to verification of users has been costly, difficult for departments to implement, and hard for people to use (National Audit Office, 2017). Can the UK take advantage of Blockchain technology to create a more inclusive digital environment?

The author performed "competitive intelligence analysis" by investigating whether other states are modernising their identity infrastructure with Blockchain. They discovered how India has started to experiment with building new services on Blockchain (Chowdhury and Saha, 2021). They also found theoretical explorations of how a state could craft a biometric identity system utilising Blockchain (Páez et al., 2020) - but with little exploration of user-needs.

4.2 Potential Solutions

The World Wide Web Consortium's proposal for "Decentralised Identifiers" (W3C, 2021) defines several methods of Public Key Infrastructure (PKI).

This would allow a diverse set of participants to make identity claims about themselves and others - see Figure 02. By recording these claims on a Blockchain, data subjects can prove when a claim was issued and who issued it. The issuer would also be able to unilaterally revoke their claims - although they could not expunge the record of the original claim from the Blockchain.

The system also relies on all parties being able to keep their private keys safe - a well known failing of PKI systems (Ruoti et al., 2015).

Figure 02 - DID Diagram © 2021 W3C Decentralized Identifiers (DIDs) v1.0

Could a state-backed blockchain be useful in providing a digital identifier to all of its citizens?

There are some superficial reasons to think so. Immutability of data may be attractive given how the hard drives of the UK's former National Identity Register were physically destroyed by a newly elected government (Boersma et al., 2014). An "always-on" connection to an online database is now possible given the surge in mobile internet access across all sectors of society (Ofcom, 2022).

But these need to be set against the complexity and uncertainties of the problem space. These sorts of intrinsic issues with multi-stakeholder systems are commonly referred to as "wicked problems" (Mertens, 2015).

4.3 The ethical role of the modern professional

Data Analytics professionals must identify the risks to both the user and the organisation from new technology. This can be via literature review or user research.

For the above example, a literature review reveals there are long-standing issues with the usability of PKI (Whitten and Tygar, 1999). Additionally, any system which relies on biometrics as a critical factor in authentication must contend with the fact that not all users will have those biometric markers. For example, some people have genetic mutations which prevent the development of fingerprints (Nousbeck et al., 2011).

The author believes the ultimate role of the Data Analytics professional is to stop the spread of unethical practices. As a member of the Chartered Institute for IT, it behoves the author to act under the auspices of their ethical framework.

This also means understanding the environmental impact of technology (Crooks et al., 2009). Given the continuing climate crisis (IPCC, 2022) and the exorbitant energy cost of Blockchain's "Proof of Work" algorithm (Schinckus, 2021), it is the author's professional opinion that all Blockchain technologies - whether in the identification space or otherwise - should be actively resisted.

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Copyright and Copyleft

This document is 🄯 Terence Eden CC-BY-NC https://creativecommons.org/licenses/by-nc/4.0/

It may not be used or retained in electronic systems for the detection of plagiarism. No part of it may be used for commercial purposes without prior permission.

Any source code is under the MIT Licence

This document contains public sector information licensed under the Open Government Licence v3.0. https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

The final chapter of this dreadful book! Will it be an interesting or educational one?

Interoperability is a big problem. Multiple incompatible chains which can't easily communicate with each other. Some research in interledger protocols like Quilt. Also Tendermint which publishes packets from one chain to another - relies on the receiving chain to check the sending chain has published the corresponding packet.

Privacy. All transactions must be public due to its nature. How to obfuscate? Could homomorphic encryption work? What about Zero Knowledge Proofs?

• Indistinguishability Obfuscation
  • Not ready yet
  • Code is scrambled and will only run correctly if run in the right order.
• Homomorphic encryption
  • Ability to run computations on encrypted data without first decrypting it.
• Zero-Knowledge Proofs
  • No explanation given
• CoinJoin
  • A way of money laundering
  • Mix coins together and distribute back to all parties.

Standardisation. Early work being done by ISO/TC 307. There's also OS1 - the open chain standard.

Assignment

Scalable blockchain solutions Read the research paper at https://www.tik.ee.ethz.ch/file/74bc987e6ab4a8478c04950616612f69/main.pdf.

Answer the following questions:

• How can sharding work for scaling blockchains?
  • Separate shards for different functions.
  • Split the consensus plane.
• How speed of PoW based proof works can be improved?
  • Larger blocks
  • Smaller time between blocks
  • Better gossip protocols
  • More efficient use of bandwidth - possibly via a P2P protocol.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

I love how they've made up the acronym BaaS!

Apparently both IBM's Bluemix and Microsoft's Azure offer Ethereum blockchains. Electronic Government as a Service (eGaas!) might come soon.

Azure' blockchain is called Bletchly. Has "cryptlets" which are external to the chain oracles. Can be written in any language (LOL) and run in a container.

Designed to be a "click and run" service.

IBM's offering is Hyperledger Fabric.

And... that's it! No explanation of what they do, why you'd use them, or what the downsides are. A pathetic penultimate chapter.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Regulatory frameworks need to be followed by businesses. There is a cost for compliance. Need to ensure that their blockchains are secure and suitable for enterprise use.

Blockchain isn't an application; it is a network.

Contracts and transactions need to be audited.

Can't store personal data on chain. What if transaction data is "leaked" - who is responsible? The whole network?

Do financial institutions want their transactions viewable by a 3rd party?

Having a shared AML / KYC database would reduce costs & duplication. But a single wrong entry would worm its way into all systems.

There are some practical attacks - including double-spending and majority attacks.

Smart Contract security if a difficult problem. Formal verification of the code might be possible. Lots of bugs in smart contracts - often leading to catastrophic results & theft. But code is law, so you're out of luck. There's no court to argue in front of.

Timestamp and block ordering manipulation is possible, as is call stack depth limits.

Reentrancy bugs allow a function to be called before it has finished - which can lead to multiple withdrawals.

And, of course, the standard programming bugs.

End-point security. How do users ensure the security of their private keys?

Privacy - all transactions are public, so possible to build a "social graph" of users and the flow of money. Can be disrupted with "mixing protocols" - because money is fungible (!!) a shared wallet can take in coins from multiple parties and redistribute them.

"Coloured Coins" - attaching metadata to coin which could represent an asset. Allows for the tracking of specific coins. Can be used to record assets like share certificates and voting rights.

Assignment

Read the paper “Securify: Practical Security Analysis of Smart Contracts”

Answer the following questions:

• What is the main challenge required to be addressed in order to build a smart contract security analyser?
  • Smart contracts are Turing Complete.
  • Reports may contain many distracting false alarms.
  • May rely on spotting "common" bugs and fail to catch esoteric ones.
  • May take a long time to analyse code.
  • May take a lot of memory to analyse code.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Bitcoin is limited to 3-7 transactions per second. Ethereum isn't much better - max of about 20.

Can possibly be solved by on-chain solutions like increasing block size. Or off-chain - where transactions are performed offline, then bundled up.

Or, an abstraction where different layers of the chain are responsible for different things.

Controversy over Bitcoin block size proposals.

Ethereum has no fixed block size - instead the gas limit restricts the amount that can be created.

Or, instead of block limit changes, decrease the time between blocks. Ethereum is down to 14 seconds - which is better than Bitcoin's 10 minutes (!).

Invertible Bloom Lookup Tables - basically transferring information about the state, rather than the full state.

Sharding - similar to how traditional databases work. Multiple nodes splitting the tasks between them.

State channels - use out of band messaging for state updating.

Private blockchains - fast because participants don't need to mine.

Proof of Stake is faster than PoW (no evidence or explanation given.)

Sidechains - take things off main to a faster chain (why not move everything there?)

Subchain - poorly defined.

Tree chains - rather than a 1 dimensional chain, use a structure like a binary tree.

Bitcoin-NG - use leader blocks for PoW and microblocks (which don't require PoW).

Layer 2 solutions - like Lightning. Introduced in 2016, allows for off-chain instant payments.

Better consensus protocols. Either implemented in hardware, or move away from PoW.

Assignment

Read the paper at https://lightning.network/lightning-network-paper.pdf.

Answer the following questions

• Do micropayments channels require trust?
  • No. They are trustlessly deferred to a later date.
• What is the use of SIGHASH_NOINPUT?
  • The two parties sign the transaction - but don't broadcast it to be validated.
  • Can allow for spending before signing from all parties.
• What is HTLC?
  • Hashed Timelock Contract
  • Lock a transaction via a commitment which can only be valid after a certain date
  • Revocable
• How can malleability be resolved?
  • Forking change to Bitcoin.
  • New sighash types
  • Allows parties to spend contracts without either being able to broadcast to the chain until both parties agree.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

The first semi-practical module! Including how to write a smart contract on Ethereum.

A variety of "testnets" to play on before deploying to main. Also possible to use a private net.

Use of the geth client from https://geth.ethereum.org/downloads/

Terence Eden is on Mastodon

@edent

Replying to @edentThe Certified Blockchain Professional book is poorly edited garbage.
I'm on the first practical module.
I start by creating a genesis block at `~/ethpriv/`
But, in the next command, it tells me to use `~/etherprivate/`!
Oh, and the rest of the switches are invalid… pic.x.com/za5hqnci1a

---

*sigh*

On to Solidity. The language of "Smart" contracts. The book says "Its syntax is closer to both JavaScript and C."

Nooooo! Why would you write anything contractual in either of those languages?

Solidity is statically typed so its syntax is checked at compile time.

Data types include bool and int (signed integer) and uint (unsigned).

address is a 160bit value.

balance the balance of the address in Wei.

send a method.

address to = 0x6414cc08d148dce9ebf5a2d0b7c2201234567890;

address from = this

if (to.balance < 10 & from.balance > 50)
   to.send(20);

Usual range of arrays, loops, etc. Functions and Libraries also available. Libraries can't have state or use inheritance, nor can their receive Ether.

Events can be written to the chain, which is useful for notifying a change of state, or the occurrence of an event.

Functions can be internal to the current contract - or they can be external; calling other contracts.

The throw allows a contract to be rolled back.

Can use Web3.js to communicate with Ethereum nodes via RPC using JS.

Metamask is a Dapp browser which lets people run Ethereum Dapps in the browser. Injects a Web3 object into FF & Chrome.

Then lots of tedious copy and pasting with no explanations - and lots of outdated commandline examples.

Oracles

Data feeds which enter data from the real world into smart contracts.

Use TLS Notary to "prove" provenance of the data. But essentially just saying that website X said Y at Z time.

IPFS

Use of decentralise storage, addressed by hash.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Can IOT record their data to a Blockchain? Probably not using PoW as they're too underpowered.

But there are advantages to recording in a decentralised way rather than reporting to a centralised "command and control" server. Centralised services might not be able to cope with billions of transactions. (hahaha!)

Similarly, storage will be cheaper if it is decentralised. (Why? How?)

Less risk of DDoS. (Note, Blockchain can and does suffer from DoS attacks.)

Devices can choose to pay each other for services. (Again, why?)

ASSIGNMENT

Visit https://www.iota.org/.

Answer the following questions.

• What is IOTA?
  • A blockchain for IoT
• What problem it is trying to resolve?
  • Costs are too high
  • Data is centralised
  • Uses Directed Acyclic Graphs rather than a single chain
• What are the common use cases of IOTA?
  • None, really. Small sensors which need to record data in a semi-verified way. Perhaps in-car sensors?
• How does consensus work in the tangle?
  • "The Tangle is IOTA's network. It immutably records the exchange of data and value. It ensures that the information is trustworthy and cannot be tampered with nor destroyed."
  • For every transaction sent, a node must confirm two others using PoW.
  • There is a central(!) co-ordinating node in the Tangle.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Where and how will blockchain revolutionise industries? Another hopelessly optimistic chapter.

Can blockchain prevent the "horsemeat" scandal? Transparency of supply chains for consumers and industry. (No, because of the Oracle Problem)

Cost saving; if all participants in food supply chain starting from the source to supermarket share the same blockchain, there is no need to use seperate [sic] IT systems to manage records and inspections.

Ignore the competitive advantage supermarkets have in supply-chain and logistics software.

Ethical sourcing - but, again, how do you tie a chicken's welfare to the box, or the egg, that you buy?

Identity. PKI as the solution to all life's ills. Ignores how hard it is for users to use of manage.

blockchain-based online digital identity allows control over personal information sharing. Users can see who used their data and for what purpose and can control access to it. This is not possible with the current infrastructures which are centrally controlled.

Again, nonsense. This is possible with a centralised system. But what bit of Blockchain prevents someone from viewing data they've previously had access to but you've rescinded?

Zooko's Triangle - name protocols must be human-readable, secure, and decentralised.

Namecoin. A fork of Bitcoin. A way to register key/value pairs. Storage and transfer of keys, 520 bytes(!) of data, and a cryptocurrency. Namecoin is a merged mining protocol. The Namecoin block is created and the hash of it is added to a Bitcoin block. Supposed to solve the "slowness" of DNS - but no mention of speed given.

Post-trade settlement. A possibly useful use-case! Removal of central clearing houses - and other custodians. A shared ledger gives a single view of the truth. Useful for regulators as well.

Decentralised storage. Like any P2P system - but with an incentive to store the file.

ASSIGNMENT

• Read the whitepaper from sovrin at https://sovrin.org/wp-content/uploads/2018/03/Sovrin-Protocol-and-Token-White-Paper.pdf
• What problems does online identity face and how is sovrin aiming to solve them?
  • Self Sovereign Identity. Proving who I am without intermediaries.
  • "Where is the digital equivalent of a passport, driver’s license, or birth certificate that we can just “show” to a website to register, login, or verify our rights and privileges?"
  • Use of W3C Decentralised IDs to *hand wave* put PKI on the Blockchain.
  • Verified credentials. An issuer signs a claim, the owner countersigns the claim, a verifier verifies the signatures. Put it all on a chain.
  • Selective disclosure allows a zero-knowledge proof. E.g. show you're over 18 rather than exact date of birth.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

What industries can be disrupted by Blockchain? Well, what does Blockchain do?

An append-only database solves the "problem" of data disappearing. Non-repudiation might be useful somewhere.

Blockchain also acts as a proof-of-timestamp service. That is, you can prove that a datum was added no-earlier than a specific time.

Decentralisation might also lead to disintermediation. Do you need an insurance agent if you can go direct to the market?

Here's a typical sentence from the book:

The resulting artifacts/collateral of the blockchain garage engagement are envisioned to be instrumental in socialization and in providing a blueprint for a business seeking executive sponsorship and the necessary funding for first project.

Can you translate that into something intelligible? I can't!

There's also a content-free piece of slideware from IBM to browse.

Insurance

I've written about this before - "In praise of slowness". Could Blockchain help insurance? Maybe - but not as much as getting the basics of technology right. A smart contract may be faster (LOL) but sometimes slowness is a feature, not a bug.

Post Trade Settlement

This is one of the few areas where I think Blockchain could be useful. Large institutions with mutual distrust could use a Blockchain to record and reconcile transactions.

It could reduce the need for intermediaries like clearing houses.

Financial Crime

KYC (Know Your Customer) and AML (Anti Money-Laundering) are key for preventing crime.

Blockchain can provide a solution to this problem by securely sharing a distributed ledger between all financial institutions that contain verified and true identities of customers.

LOL! So much for a decentralised anonymous currency!

AML - it is possible to trace transactions through a chain. But also possible to obfuscate.

Government

Border Control

It suggests a blockchain containing a "blacklist" (hateful phrase) of undesireables. But there's no explanation of why a blockchain is necessary - a shared DB would work just as well. Similarly, when a country revokes a passport it could broadcast that it is no longer valid. But lots of countries don't. Adding blockchain to the mix won't suddenly conjure up administrative competence.

Voting

I've previously written about the "Usability of Key Distribution in BlockChain Backed Electronic Voting"

Security is provided in the form of integrity and authenticity of votes by using public key cryptography which comes as standard in a blockchain.

OK, but how do you distribute those keys? How easy are they to use?

Judicial

to prove evidence (such as a video) has not been tampered with by hashing files into a blockchain during the formal intake procedure. etc.

OK, but is this a problem? Does evidence routinely get tampered with? What if it is tampered with before adding it to the chain?

Media

More wishful thinking.

Blockchain can provide a network where digital music is cryptographically guaranteed to be owned only by the consumers who pay for it.

and

illegal copying of digital music files can be stopped altogether because everything is recorded and owned immutably in a transparent manner on the blockchain.

Again, I've written before about why this is wide-eyed nonsense - NFTs means the future value of art is zero.

Healthcare

In healthcare, major issues such as privacy compromises, data breaches, high costs, and fraud can arise from lack of interoperability, overly complex processes, transparency, auditability, and control.

OK, but Blockchain doesn't solve that. There can be multiple incompatible chains. The cost of the tech is high - and complicated to use. Once data is leaked onto a chain it can never be revoked.

Another burning issue is counterfeit medicines; especially in developing countries, this is a major cause of concern.

No details of how a Blockchain with solve this. Physical certificates can be removed and placed on counterfeit drugs.

Qualifications Needed

Apparently the industry is crying out for people with Blockchain qualifications. The book doesn't list any good ones - but suggests that business knowledge, and legal / regulatory knowledge are key.

Assignment

Impact on industry

• Visit https://www.ibm.com/blockchain/supply-chain. Understand the benefits that blockchain can provide to supply chain industry.
  • Multi-Party disputes might disappear. But only if smart contracts are properly written - and all parties faithfully record correct information onto their chain.
  • Labour disputes might disappear because timesheets are on a DLT. But that assumes the employer signs them off.
• Read the report by DHL here https://www.dhl.com/content/dam/dhl/global/core/documents/pdf/glo-core-blockchain-trend-report.pdf. Understand how global movement of freight can be streamlined using blockchain.
  • Very wishy-washy. Signing transactions is useful to prevent post-fact manipulation.
  • Can it tell you if supplies have been ethically sourced? No - only that they claim to have been.
  • Will only work if every one of tens of thousands of organisations all agree to simultaneously use the same chain.
  • Smart Contracts could allow for automatic payment but - again - that could happen now. Poor processes don't go away just because they're online.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Covers the basics of AI and ML. But, again, no real details.

Links to nonsense like https://singularitynet.io without any commentary.

Effectively boils to two things.

1. Get data from the Blockchain and use it for deep learning.
2. Smart contracts which use AI to self-adapt. Which, of course, makes the code even more obscure!

The examples they give are ridiculous:

A smart contract can respond to security incidents quicker and accurately. E.g., if a hacking attempt is discovered the smart contract can shut down accounts, can adjust gas consumption (ethereum), can move funds to another backup contract.

That doesn't require AI!

Natural language processing can also be an option to introduce in smart contracts, to understand real contracts and execute them.

Now they're no longer deterministic programs! Much better to choose a better language to write them in.

Smart contracts can also be formally verified with formal verification methods (e.g. SMT solvers) but Al can also play a role by improving the verification process.

Hmmmm... maybe. But that's not AI on the Blockchain. That's like saying IDE on the Blockchain when you mean "writing code in an IDE".

Blockchain governance can also be Al driven, which can make changes to consensus, improve security and maintain the ledger by reacting to the changing environment.

Errr? So the owners of the DAO no longer get a say and it becomes self-governing? We're in to properly off-the-wall territory here!

This leads on to an interesting discussion of general-purpose rational agents (Machina economicus). A machine making self-interested decisions. Of course, nothing about this requires Blockchain.

ASSIGNMENT

Al and Blockchain

Research answers for the following questions. Provide examples.

• Can Al in blockchain solve energy consumption issue?
  • LOL! I suppose AI (or quantum woo) might be able to design more efficient ASICs for running computations. Or it could generate algorithms which are work-bound but which don't require more energy.
• Can Al result in increased security of blockchain?
  • Meh. Formal verification would be useful. As would automated scanning. Both could benefit from low-levels of AI.
• Can Al help in providing data from blockchain for machine learning?
  • Errr...? No. All the blockchain contains is a record of transactions. So what would a trained model look for? When transactions take place? Who they go to / from? Might be interesting to predict when spikes / lulls take place in order to take advantage of them.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

A short and pointless chapter. No real discussion of how DAOs actually work, or example code. No discussion of the social implications.

DO - Decentralised Organisation. A program running on a blockchain - as one or more smart contracts. Parties interact via the DO. Requires humans to input data and execute logic.

DAO - Decentralise Autonomous Organisations. Same as above but without the humans. Operates based on information on-chain. No legal status and questions over jurisdiction given they run in multiple places.

DAC - Corporation. Same as a DAO but can pay profits / dividends to shareholders.

DAS - Society. Imagine if all government services were smart-contracts. Land registry, marriage certificates, birth certificates, passports etc. Can't be censored or capriciously denied service.

The General Theory of Decentralized Applications, Dapps

DApps are:

• Open Source
• Records must also be open and stored on chain
• Use a native token for payment
• Generate tokens according to Proof of Value (which may be PoW)
• Changes only allowed by majority consensus

Hilariously:

The most famous DAO project is The DAO, which raised $168 million in its crowdfunding phase. The DAO project was designed to be a venture capital fund aimed at providing a decentralized business model with no single entity as owner. Unfortunately, this project was hacked due to a bug in the DAO code, and millions of dollars’ worth in Ether currency (ETH) was siphoned out of the project and into a child DAO created by hackers. A hard fork was required on the Ethereum blockchain to reverse the impact of the hack and initiate the recovery of the funds.

ASSIGNMENT

• Study DAO at https://en.wikipedia.org/wiki/Decentralized_autonomous_organization
• Study the DAO at https://en.wikipedia.org/wiki/The_DAO_(organization)

Answer the following questions:

• What is a DAO?
  • A set of smart contracts, running on a Blockchain, which is co-owned by multiple people.
• When was the DAO attacked?
  • Launching in April 2016 and attacked in Jun 2016. LOL!
• What was the outcome?
  • About $50mm worth of ETH went to the attacker(s). Naughty!
• How was it mitigated?
  • In order to "bail out" the DAO, Ethereum instigated a "hard fork" which effectively returned the money.
• Was it really mitigated? What happened to the funds (ether)?

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Again, a terribly written & edited chapter. I had to revert to the sources on Wikipedia to understand it.

Ethereum is a Turning-complete language for running decentralised apps (dApps) and smart contracts on a blockchain. By contrast, Bitcoin's scripting language can only perform the operations necessary to financial transactions.

A DAO hack forced a hard for into ETC (classic) and ETH (Ether).

ETH is a reward for miners for verifying and validating transactions. It is spent to pay for the execution of contracts on the Ethereum Virtual Machine (EVM).

ETHASH is the PoW. Approx 3x faster than Bitcoin. No limit to the number of ETH.

Public / Private key pairs as standard. Addresses are a 20b code derived from the public key. Addresses represent accounts.

Ethereum is a transaction driven state machine. Transactions between accounts represent state transactions. The function is

1. Check validity of syntax, cryptographic signature, and nOnce.
2. Calculate the the sending address from the signature.
3. Calculate the transaction fee (how?!)
4. Sender's account balance is checked and deducted. Return an error if balance is insufficient.
5. Increment nOnce
6. Provide enough ETH (gas price) to pay for the transaction.
   • ETH is charged per byte (!) proportional to the size of the transaction.
7. If the destination doesn't exist - create it.
8. If the destination is a smart contract - execute the contract.
   • The contract will run for as long as there is ETH. This may not be enough to fully execute the contract.
9. If there is insufficient balance or gas, The state is rolled back - except for fee payments (of course!)
10. The remainder of the ETH (if there is any) is sent back to the sender - and fees paid accordingly.
11. The function returns the final state which is stored on the Blockchain.

Ethereum is a project which attempts to build the generalised technology; technology on which all transaction- based state machine concepts may be built.

All stems from Ethereum's Yellow Paper.

Good explainer of the Yellow Paper.

Ethereum Virtual Machine - EVM. Runs bytecode. Simple stack execution model. LIFO queue of 1,024 elements.

Requires gas (money) to run - which makes infinite loops and DDoS expensive and therefore "impossible".

EVM is deterministic and isolated from the network and filesystem.

Smart Contracts

First defined in Szabo's "Formalizing and Securing Relationships on Public Networks"

Smart contracts are self-enforcing as opposed to legally enforceable. This idea might be regarded as a libertarian's dream, but it is entirely possible and is in line with the true spirit of smart contracts.

Ignores the fallibility of programmers!

Solidity

Language for writing Ethereum Smart Contracts. Compiled using solc to EVM bytecode to be executed on chain.

Remix is a web-based IDE.

Absolutely no discussion of how either the language or IDE works!

Supporting Protocols

Because of how poorly designed Ethereum is, there are a few supporting protocols.

Swarm for file storage. Decentralised - uses hashes to address files.

Whisper for messaging. A communications protocol between dApps. Small message size and not real-time. Untraceable.

ASSIGNMENT

Download the Ethereum yellow paper

Read the paper and answer the following questions

• What is world state and how it is maintained?
  • A map of addresses (160 public keys) and states (a data structure).
  • Merkle-patricia tries - with every node verifying transaction.
• What is a block in Ethereum?
  • A collection of hashes, representing transactions, bundled together with a representation of the end state.
• Why is Gas mechanism introduced?
  • This introduces a cost per computation. This means that infinite loops or Denial of Service attacks are too costly to perform. It also works as a way to reward miners.
• What is EVM and how does it work?
  • A simple state transaction machine with a deliberately limited instruction set. Isolated and secure. It computes until it finishes, or runs out of gas.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

• Permissioned Ledger
  • All the participants are known and trusted. This removes the need for PoW or other consensus mechanisms.
  • Doesn't have to be "private" - multiple trusted entities can be added.

• Permissionless

  • Decentralised (ha!) so anyone with sufficient resources can become a node
  • Don't have to be "public", just that the entities are not sufficiently trusted without a consensus mechanism

• Hyperledger

  • A collaborative effort by members (who?) to create open source Distributed Ledger frameworks for cross-industry blockchain things
  • Focus on reliability and performance
  • Consists of:
    1. Blockchain projects
    2. Tools / modules to support the projects
  • Part of Linux Foundation
  • Projects usually contain:
    • Consensus layer - how to validate transactions and agree on network activity
    • Smart Contract - business logic in code which run automatically on the blockchain
    • Communications - message transmission between nodes
    • Security / Cryptography - algorithms / modules for Privacy, Confidentiality, Non-repudiation
    • Data Stores - how and where to store the state of the ledger, including databases
    • Policy - management of endorsement policy and consensus policy
    • API / SDK - how 3rd parties can programmatically interface with the blockchains

• Fabric

  • IBM's permissioned distributed ledger
  • Multiple languages can be used to develop smart contracts
  • Based on Docker
  • Chaincode in a sandbox
  • Designed to be scalable, private, and confidential
  • Modular design for flexibility
  • Requires membership services to make sure only trusted people allowed on - secured by Enrollment Certificates
  • P2P storage
  • Applications typically written with a UI in HTML+JS, which interacts with the chaincode

• Burrow

  • Yet more word-salad!
  • Seems pretty similar to Fabric
  • Separation of logic and action

• Sawtooth

  • PoET is a consensus algorithm - Intel desperately trying to find a use for SGX and trusted computing.

• Cello

  • It seems there are a plethora of services to manage the services of the services which eventually run Blockchains!
  • Lifecycle management of chains

• Composer

  • Yet again, another management service.
  • Uses JS and NPM - a disaster for precision and accountability

The chapter continues to list half a dozen projects - giving a couple of paragraphs to each. But it is mostly content-free.

Most interesting is the concept of "notary services" - temporal validation and ordering. Timestamping, basically.

Assignment

Download the paper “Hyperledger Fabric: A Distributed Operating System for Permissioned Blockchains”

(This is a long and tedious paper!)

• What services does a membership service provide?
  • The MSP issues cryptographic keys to members. Only authorised members are allowed to use a permissioned blockchain. So this as a gatekeeper - restricting entry. Theoretically, it could check any aspect of the service before issuing credentials.
  • The MSP can act as a federated service. That is, MSP X can choose to recognise the credentials issued by MSP Y.
• How many roles can a node take up in a Fabric network? Name the roles.
  1. Client. Issues transaction proposals to be executed by the network. They also help ordering, and broadcast transactions to be ordered.
  2. Peer. Execute transactions. Validate transactions. Maintain the ledger. Peers don't have to execute all transactions - on the subset of endorsing peers.
  3. Ordering Service Nodes. This seems vague. They come to a consensus on the total ordering of the system.
• How is Bitcoin style UTXO model captured in Fabric?
  • Unspent Transaction Output. Like in that Superman Movie - it's the fraction of a coin left over after a transaction.
  • A Key Value Store
  • > Every transaction creates one or more output states in the KVS representing the new owners, deletes the input states in the KVS, and ensures that the sum of the values in the input states equals the sum of the output states’ values.
  • Effectively they are tracked

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

One of the biggest challenges organizations face in adopting blockchain solutions is the energy intense blockchain mining. In this chapter you will be exposed to IIB Council’s proprietary framework of Sustainable, Secure and Scalable Blockchain Development based on Quantum Computing.

You can tell someone is chatting bullshit when they invoke Quantum Computing. Much like cold fusion, it has been on the cusp of revolutionising the world for the last 50 years.

Proof of Work (PoW) is a necessary(?) evil to prevent double-spending and other attacks against Blockchains. Making the cost (via energy prices) prohibitive for anyone to mount a 50% attack.

It is estimated that the total electricity consumed by Bitcoin miners currently is more than that of the Czech Republic at 71.12 Terawatt hash (TWh) … and all that power is in a way wasted; in fact, no useful purpose is served … Environmentalists have raised real concerns about this situation. … the carbon footprint is also very high, currently estimated at around 387 kg of CO2 per transaction.

Good to see them acknowledging this!

Can PoW be redirected into something useful? As mentioned in a previous module, the obsolete "PrimeCoin" was an attempt to do this.

I wonder if the hashing power could be used to break private keys? Back in 2003, a team were trying to crack the original Xbox signing key

That was "only" a 2048 bit key. Is there now enough hashing power in the world to find the private key? If so, would that be a useful form of PoW?

Instead, they discuss Proof of Stake and Proof of Coin. Which, while interesting, still require you to have burned energy in order to get the coins in the first place. Proof of Burn is just ridiculous - intentionally mining and then destroying the coins!

Nonoutsourceable puzzles

Nonoutsourceable puzzles are a scheme that allows miners to claim rewards for themselves; consequently, pool formation becomes unlikely due to inherent mistrust between anonymous miners.

I don't get that. It prevents collusion between anonymous miners - but doesn't stop large pools of known actors. So, again, it leads to centralisation. There's a paper about it which is very technical.

A brief discussion about Quantum Computing follows, setting out the history and some basic definitions. Could Qubits be used to break encryption? Theoretically. Can they be used for faster-than-light information transfer? No.

There's a (broken) link to Qiskit which attempts to give basic tutorials in Quantum Computing.

Grover's Algorithm and Shor's Algorithm. Classic RSA is based on the fact that it is hard and slow to find prime factors. If that is no longer the case, lots of algorithms fall to quantum supremacy.

Lots of the discussion of "Quantum Resistant" algorithms sound like pseudo-science word-salad. There are some interesting resources on the NSA site - but it is hard to take seriously when there are no practical Quantum Computers to test on.

ASSIGNMENT

• Visit https://digiconomist.net/bitcoin-energy-consumption and estimate how much electricity will be used by the end of 2018 by Bitcoin.

  • Here's the current graph
  • 
  • Energy usage appears to be stable - driven, I assume, by rising energy costs. Previous periods of stagnation have been followed by slight dips, so I'd expect this year to end just under 200TWh.

• Answer the following questions

  • What is the carbon footprint of a single transaction of bitcoin?
    • 
  • What is the amount electricity consumed by a single bitcoin transaction?
    • 
  • Assuming Bitcoin is a county, and if compared with other countries, where does Bitcoin energy consumption stands in comparison? Name the country that comes just after the current level of Bitcoin energy consumption.
    • 

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Another poorly edited chapter full of grammatical mistakes and logical leaps. Oh well! I've booked this course, so it's too late to back out now.

This is a massive chapter - and it took me a couple of sessions to get through it.

Bitcoin … has proven to be extremely secure and stable from a network and protocol point of view. As a currency, bitcoin is quite unstable and highly volatile…

Amazing! Yes, there have been few successful attacks. But its throughput is low and it doesn't work as a store of value.

It goes into a little of the history of digital currencies (as distinct from payments). For example Chaum's Blind Signatures paper. Chaum's paper is brilliant - an interesting scheme for issuing ballots, or money, which is relatively anonymous but easy to be de-anonymised with the consent of the parties. One core limitation is that it relied on a central authority to issue, check, and invalidate notes.

Similarly, the early e-Cash paper makes some interesting ideas - but it still relies on a central authority to check for double-spending. It also allows that central authority to revoke any coins which it has been issued.

The term Proof of Work emerged and got popular later with Bitcoin, but in Wei Dai's B-money a scheme of creating money was introduced by providing a solution to a previously unsolved computational problem. It was referred in the paper as a solution to a previously unsolved computational problem.

Seriously, this is the level of proof-reading in this book!

Anyway, hashCash was originally designed to stop spam by making it computationally unfeasible to send large amounts of spam.

The B-Money Paper presents an early form of cryptocurrency - using distributed databases where coins are created through solving mathematical puzzles. There's also a prototype smart contract as well. It also recognises the rapid advance in computing power which makes crypto so problematic.

Then there's the Auditable, Anonymous Electronic Cash paper from 1999. Introduces Merkle trees to represent coins and Zero Knowledge Proofs to display ownership.

Bitcoin can be defined in various ways; it's a protocol, a digital currency, and a platform. It is a combination of peer-to-peer networks, protocols, software that facilitate the creation, and usage of the digital currency named bitcoin. Nodes in this peer-to-peer network talk to each other using the Bitcoin protocol.

A bit sycophantic, but OK. I hadn't realised that Bitcoin was the protocol and bitcoin was the currency. Which one is the monster?

Private keys it Bitcoin are 256 bit secp256k1 ECDSA curve numbers. They are usually converted to Base58 (with a few other bits) to make the Wallet Import Format. This does not seem to make the string much easier to use. So what's the point? Mini private keys can be used where space is limited, like QR codes. (This seems odd, QR should have no problem with a 256 bit number.)

If you need to refresh the relevant cryptography concepts, you can refer to Chapter 4, Public Key Cryptography, where ECC was explained.

I am in Chapter 4. It has not described Elliptic Curve Cryptography. Ah, this book is plagiarising content from elsewhere!

Terence Eden is on Mastodon

@edent

Replying to @edentAnother (sincere) Bitcoin question!
Can someone explain *why* the Wallet Import Format is useful?
The Base58 string isn't much shorter, and it doesn't obfuscate the private key in any way.
So what's the point in them? pic.x.com/TEcVyHQEct

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Terence Eden is on Mastodon

@edent

Replying to @edentAmazing!
The book says "If you need to refresh the relevant cryptography concepts, you can refer to Chapter 4, Public Key Cryptography"
But this *is* chapter 4…?
Ah, they've just copied this text from a DIFFERENT BOOK!
google.co.uk/books/edition/… pic.x.com/FNP6Q6GPer

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The algorithm for constructing a wallet address - Public Key → SHA-256 → RIPEMD-16. Points to an utter failure of usability.

Happily admits that Bitcoin has no intrinsic value, but points to Metcalfe's law of networks to show proportional value to participants.

The Bitcoin structure is interesting but, again, rather theoretical. I don't understand why double SHA-256 is used.

A high level discussion of SPV and Stratum nodes. All very poorly explained.

Repetition of PoW. Bitcoin has a possible 21 million coins which are generated at a decreasing rate. There's no explanation for why they think this counters inflation.

Brief discussion of the "Script" language for bitcoin spending. Not Turing complete and no loops (to avoid hanging the network). It's a Forth style(!) language with Reverse Polish Notation.

UTXO - remaining scraps of coins not spent. Sounds like the plot of a Superman film.

Terence Eden is on Mastodon

@edent

Replying to @edentOn the left, the EC Council's "Certified Blockchain Professional" book.
Note how it says "Businesses can use the following logo" but doesn't present an image?

On the right, the Packt book "Mastering Blockchain" - where the text has been copy-and-pasted from! pic.x.com/D4ja10WgUQ

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Wallets don't actually "store" bitcoins. They are private keys which prove ownership of coins on the network. Most keys are non-deterministic. But you can have deterministic wallets which use human-readable words to create a keyphrase which "unlocks" the keypairs.

A "paper wallet" is just a bit of paper with they key printed on it. Challenge to keep safe.

Privacy - all transactions are public. Can use "mixers" - which is risky, but can disrupt graph analysis.

KYC is required in many parts of the world - as is effective securities regulations.

Various alternatives / extensions to Bitcoin to deal with its slowness etc.

Forking - either intentional or unintentional. Unintentional usually due to bugs. Hard forks require a new chain and new software. Soft fork, usually can continue working on the old chain with old software but might not be able to fully participate due to change in protocols.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

The key to remember is that "mining" really means "solving cryptographic puzzles in order to validate a transaction". The original Bitcoin paper recommends "Proof of Work" on the flawed assumption that would dis-incentivise fraudulent transactions.

Solo mining means getting a computer and running the mining software on your own hardware. This was practical in the early days of Bitcoin, but not really feasible since the invention of specialised hardware. Because...

Mining Pools are groups of people with a vast array of hardware. The act as mini-share-based corporations. All members of the pool share the rewards. It's like a workers' co-op (but evil). Popular models include Pay Per Share (everyone gets an equal cut) and Proportional Fee (where those who contribute the most computing power get a proportionally higher reward).

There's a tedious discussion about the design of mining rigs. Basically Linux and the most powerful GPU you can find. With plenty of cooling.

The transition from CPU (general purpose hardware + general purpose algorithm) to GPU (general purpose hardware + specialised algorithm) to FPGA (Specialised hardware) to ASIC (application specific integrated circuits). None of which are profitable for the individual user any more.

The Sybil attack (51% or, more properly, 50% +1) is a reputation system attack which is possible when a majority of the mining power is controlled by one entity (or multiple entities acting in cohort). This doesn't occur in trust systems like permissioned blockchain.

A 51% attack can lead to double spending, reversing transactions, and total control of the ledger. This has happened several times. It is a feature of powerful pools. The only proposed solutions involve yet more Proof of Work.

Trust systems use computational power of the network to validate a transaction.

The "assignment" is to install PrimeCoin.

The PoW isn't mindless hashing, it's looking for mathematically interesting prime numbers (Cunningham chain and bi-twin chains). Which is fine, I guess. Primes are hard to find, but quick to verify. That said, PrimeCoin appears to be abandoned.

Overall, a rather confusing and vague module. Like most Blockchain texts, there's lots of handwaving.

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Part of the problem with this book is that it is so credulous. It takes almost everything at face value and rarely presents a downside to the technology. It makes it very hard to treat it as an objective learning experience. It's also very sloppy when it comes to defining terms - so I spent a bunch of time looking up what it was talking about.

Onto the notes:

Tokenization is the process of converting rights to an asset into a digital token on a blockchain. Real-life examples such as gold, real estate, and stocks can be represented on blockchain using tokens.

OK, but all this is really doing is storing a certificate of ownership on a public ledger. Useful for things like land (already mostly public). Handy to see when items have been traded. Could also be bad - do you want everyone knowing your bank balance or what cars you own?

“verifiable digital scarcity”. … Non-Fungible Token protocol is defined in ERC-721 http://erc721.org Standard is defined here: https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md

The first website has a broken certificate. There's a better explanation at https://fulldecent.blogspot.com/2018/06/nontechnical-what-is-erc-721.html

ERC-721 is a "smart contract" rather than a standard. It implements ownership and transference of tokens. All tokens have an ID which is a uint256 - that is 2^256-1 Handy because UUIDs and SHA3 hashes are directly convertible to uint256.

In 2013 and 2014, the alternative coins (altcoin) market grew exponentially, and many different types of alternative coin projects were started. A few of those became a success, whereas many were unpopular due to less interest and as a result, they did not succeed. A few were pump and dump scams that surfaced for some time but soon disappeared.

That's a rather charitable reading of the situation! Would benefit from some hard numbers behind it. Also, why did these altcoins come into being? What was their purpose? Can a decentralised currency really fail? Doesn't the chain live on forever?

Some altcoins set out to address Bitcoin limitations such as privacy. Some others offer different types of mining, changes in block times, and distribution schemes.

This is interesting from an economics point of view. Obviously, Bitcoin isn't perfect (nothing is) but it is now so "mature" and widespread that it is impossible to improve it without consensus. So forks need to be created.

Good - but simple - discussion of pump-and-dump scams. Don't want to allocate coins to initial miners.

Proof of burn seems ridiculous. Why would destroying value elsewhere result in more value on an unrelated system?

zkSNARKS - again, very little technical discussion. This book feels like a glossary at times.

Litecoin allows for faster transactions as compared to bitcoin due to its faster block generation time of 2.5 minutes.

At which point, you have to ask if these people are living in the real world? I can do millisecond transactions in the UK using traditional banks. Now, this is not reconciled transactions at an interbank level, but these systems need to be at least an order of magnitude faster.

Scrypt is interesting. Use of memory rather than computation. Makes it harder to develop dedicated hardware (ASIC) to run it faster. Incidentally, there's no definition of ASIC - I think this book has been cobbled together by people who expect too much of the intended reader.

ICO - Initial Coin Offering - starts out by explicitly saying they're unregulated and the some jurisdictions treat ICOs in a similar way to IPOs. KYC and AML important.

Assignment

Learn how to perform mining using dogecoin client. As mining Bitcoin has become impossible using commodity hardware such as CPUs or even early ASICs (e.g USB ASICs), this example is introduced here which allows you to experience mining using CPUs. This example will get you familiarized with how mining works and you can mine some Dogecoin to get a feel of how mining works and what’s involved. This will utilize only CPU for mining.

This feels like an odd assignment. There's a Dogecoin wallet available - but it doesn't include a miner. Indeed, it isn't really possible (let alone profitable) to mine a block on a laptop. I didn't bother with this. I don't see what I can learn from installing dodgy software and configuring it.

Perhaps future modules will discuss personal security, how to protect a wallet, and avoid phishing? And, just as importantly, how to pay taxes on what you've mined!

These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment.

Module 1 is huge. It is also fairly light on details.

This means that there is no central controller in the network, and all participants talk to each other directly. This property allows for cash transactions to be exchanged directly among the peers without a third-party involvement, such as by a bank.

This is not quite correct. The ledger itself is a centralised third-party. Other people won't recognise your transaction until it has occurred on chain.

It later goes on to say:

the most critical attribute of a blockchain is that it is updateable only via consensus. This is what gives it the power of decentralization. In this scenario, no central authority is in control of updating the ledger. Instead, any update made to the blockchain is validated against strict criteria defined by the blockchain protocol and added to the blockchain only after a consensus has been reached among all participating peers/nodes on the network.

So every other node is a 3rd party? Except in the most basic networks (two people directly connected) there will always be 3rd parties - even if it's only a hardware router. The ledger may be distributed but it is identical. That's what makes it centralised. There is only one version of the truth.

Centralized systems are conventional (client-server) IT systems in which there is a single authority that controls the system, and who is solely in charge of all operations on the system. All users of a centralized system are dependent on a single source of service. The majority of online service providers including Google, Amazon, eBay, Apple's App Store, and others use this conventional model for delivering services.

I think I understand what they're saying here. Google controls the Google services. And the only route in to Google is via https://google.com/ - except... that's not really how it works under the hood. The DNS is a decentralised system and can route users to any one of thousands of Google's CDNs. Internally, Google isn't one big server and a single link out to the real world. It is highly decentralised and distributed. And that's before we get on to the different Google legal entities (.uk, .de, .es, etc) and the different Google products. True, you have to be part of Google to launch something as Google - but that's a desirable feature. And, yes, Google's products can have downtime. But that can't be solved with better distribution - unless all you want to do is serve up static assets.

Decentralized Autonomous Societies (DASs) are a concept whereby an entire society can function on a blockchain with the help of multiple, complex smart contracts[…] many services that a government commonly offers can be delivered via blockchains, such as government identity card systems, passports, and records of deeds, marriages, and births.

I don't see how this is decentralised. Only one organisation can issue birth certificates or passports. I suppose you could have a system where every hospital in the country offers birth certificates and then places them on a chain. But that doesn't require consensus voting. Having them write to a DLT may make sense - but this doesn't explain what problem it is solving - nor what problems it may cause.

Another theory is that, if a government is corrupt and central systems do not provide the satisfactory levels of trust that a society needs, then that society can start its own virtual one on a blockchain that is driven by decentralized consensus and transparency.

But… how do you stop this non-Government system from being corrupted? Or hacked? What does consensus even mean when it comes to issuing a passport?

think about an insurance contract where a claim is paid to the traveler if the flight is canceled. In the real world, this process normally takes a significant amount of time to make the claim, verify it, and pay the insurance amount to the claimant (traveler). What if this whole process were automated with cryptographically-enforced trust, transparency, and execution so that as soon as the smart contract received a feed that the flight in question has been canceled, it automatically triggers the insurance payment to the claimant?

I really like this idea. But there are three problems. First is "Chesterton's Fence" - are there good reasons for some of those delays? What level of fraud is repelled because of them? What if the claimant is the person who delayed the plane?

The second is the "Oracle Problem" - how can the chain trust data from outside its system? If I can hack the network feed of the aeroplane arrivals, then I can trigger a massive insurance payout.

Thirdly - there is nothing stopping these payments from being faster on a regular system. The UK's "Delay Repay" system for refunding late-running train services has morphed from a paper-based exercise in frustration, to a couple of clicks on a web page, and is now moving to automated repayments.

Blockchain can provide DRM functionality in such a way that it can be enforced fully.

LOL! Nope. As I wrote in Thinking of uses for BlockChains:

A music player could look at a Blockchain and only play the music for the user who had the most recent entry in the chain. When I sell my MP3 to you, I enter your signature after mine. Now I can't play that music and you can.

Which, I guess is fine. Although it relies on everyone upgrading all their hardware and software, rebuying all their media again, and hoping that every media company uses the exact same platform. And that no-one removes the DRM from their purchases.

The analogue hole defeats this idea quite handily.

There's an excellent discussion on Preimage and Second Preimage resistance. Similarly, Collision resistance and the avalanche effect was good - but would have benefited from some practical examples. The "Merkle-Damgård construction" only gets a brief mention and could have done with a more thorough explanation.

Again, only a brief mention of the "Byzantine Generals Problem". I had to look elsewhere to understand it.

Proof of work - doesn't really explain why burning resources is useful.

Similarly, Proof Of Stake

the user has invested enough in the system so that any malicious attempt by that user would outweigh the benefits of performing such an attack on the network.

OK, but how does the user "buy in" to the network in the first place? I get that a user who acts maliciously has their stake taken away from them - but it doesn't explain how staking starts.

Distributed Ledger Technology

DLTs are permissioned blockchains that are shared and used between known participants. DLTs usually serve as a shared database, with all participants known and verified. They do not have a cryptocurrency or do not require mining to secure the ledger.

DLTs don't necessarily use blocks. Again, I would like some more information on how the technology works. Is it individual nodes verifying their own transaction and then sharing them?

Proof of Burn. I've destroyed a stake, thus making the rest more valuable. Hmmm. If I destroy all the altcoins, does that make them infinitely valuable?

The "how Blockchain works" is also light on details. Sign a transaction, propagate, validate, append, reconfirmed. I get the signing and the propagation. But what does it mean to validate? I suppose checking the signature and ensuring that sufficient funds are available?

Simplification of current paradigms: The current blockchain model in many industries, such as finance or health, is somewhat disorganized. In this model, multiple entities maintain their own databases and data sharing can become very difficult due to the disparate nature of the systems. However, as a blockchain can serve as a single shared ledger among many interested parties, this can result in simplifying the model by reducing the complexity of managing the separate systems maintained by each entity.

But the same could be said of any common database schema. The problem isn't technological - it is sociological! If you could get everyone to agree on a common model, that would be great! The problem with common models - and common systems - it that they are rigid. What if one party needs to add a bespoke field to their data?

In the financial industry, especially in post-trade settlement functions, blockchain can play a vital role by enabling the quick settlement of trades.

Is this true in reality though? Most chains are notoriously slow. And, we go back to Chesterton's Fence as above - what are the advantages of doing things slowly? Do it help prevent fraud or flash-crashes? At a retail level, people can send money instantaneously to each other using traditional banks. Could a Blockchain which requires P2P validation be faster?

Cost saving: As no trusted third party or clearing house is required in the blockchain model, this can massively eliminate overhead costs in the form of the fees which are paid to such parties.

Again, this isn't true. Cryptocurrencies are full of middle-men taking overhead costs. And, again, in the UK it is free to send money between bank accounts. So what's the advantage here?

Another burning issue is counterfeit medicines; especially in developing countries … With the adaptability of blockchain in the health sector, several benefits can be realized … preventing the distribution of counterfeit medicines.

This isn't true. OK, you can stick a QR code on a box of pills, and that code can trace the origin back. But there's nothing stopping a counterfeiter copying that code and putting it on fake medicine. A user might be able to scan a code and "claim" that pack - but nothing stops people from doing that with a traditional database.

There's only a small section on challenges - literally two paragraphs. Scalability is an issue. How does technology get adopted? What happens when it fails? Privacy is the other big issue. With an immutable record of transactions, people can see what you're buying. Similarly, private data like medical records can never be erased.

But, apparently, this tech is expected to mature around 2025. We'll see!

Assignment

Terence Eden is on Mastodon

@edent

Replying to @edentAmazing. The first assignment in the Certified Blockchain Professional course is to read the Satoshi Nakamoto paper at bitcoin.org/bitcoin.pdf

It isn't available there. Why?

Because of the weird copyright court case! bitcoin.org/IL-2021-000008… pic.x.com/QSqU4kBeWh

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Terence Eden is on Mastodon

@edent

Replying to @edentThe first hit that I could find for the paper is on the U.S. Sentencing Commission website.
ussc.gov/sites/default/…
No comment!

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What is proof of work and why it is necessary?

Use of CPU power to calculate something. That something is x where the hash h(x) starts with a specific number of zero bits. And X is the previous hash, the current transaction(s), and a nOnce. The nOnce is really what you're trying to find.

This prevents double-spending, or reversing of transactions.

What is defined by chain of digital signatures?

Each block is cryptographically signed by a node. Each block contains the hash of the previous block, which was cryptographically signed. So it is possible to walk down a chain to verify each block's signature. And to ensure that the block's content also contains a valid signature.

How can nodes stay honest?

Only accepting verifiable blocks which haven't already been spent. By not colluding with other blocks to accept or generate invalid blocks.

Where is blockchain mentioned in the paper?

It is not.

Define electronic coin

The paper describes it as a chain of digital signatures.

As part of my ongoing MSc, I have to take 3 professional training courses. I've completed my cybersecurity course, and I have a Machine Learning course booked for January. So what to do next?

There's a lot of discussion in government⁰ circles about Blockchain. As with any new tech, there are plenty of Thought Leaders™ and sales drones trying to push it. For every one person with a legitimately useful idea, there are 99 scammers and grifters.

I'm not a big fan. But - and it is a big but - I acknowledge that I might be wrong. If I am wrong, then I want to have a decent grounding in this new and exciting technology. If I am right, then I want to have credentials to help me prove my arguments. Basically, the next time someone says that I'm only dismissing an idea because I don't understand the tech - I want to whip out my certificate.

So, after discussing the matter with my tutor, I've enrolled on the EC Council's Certified Blockchain Professional course.

It is worth noting that EC Council have a bit of a poor reputation. Sadly, they were the only course provider offered.

This is a self-directed course over around 50 hours. Which means I need to manage my time carefully. It's basically watching a bunch of videos, reading a book, and playing in their sandbox lab. I've got 6 months to do it in - although the exam can be taken up until December 2022.

So this series of blog posts will be some notes to myself, some reflection, and some questions. I've no idea how I'm going to get on with it - but I have an open mind.

Here we go…!