Terence Eden. He has a beard and is smiling.

Terence Eden’s Blog

Theme Switcher:

Certified Blockchain Professional - Module 08: Decentralised Apps (Dapps)

· 500 words


Logo for the Certified Blockchain Professional.

As previously discussed, I'm doing the Certified Blockchain Professional course. It is self-directed learning, so I'm going through it at my own pace. In order to consolidate my learning, and help organise my thoughts, I'm blogging about my reflections on each module. These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment. A…

Strange Encoding Errors in TOTP QR Codes

· 2 comments · 600 words · Viewed ~285 times


A QR code.

Not really a security issue, but one which I thought was worth highlighting. It shows the peril of slightly vague specifications. When you scan a 2FA token into your authenticator app via QR code, you get presented with a bunch of information about your account. This lets you store things like the issuer and the account name. I recently scanned a code, and it displayed my name as Terence+Eden. …

Certified Blockchain Professional - Module 07: Ethereum

· 750 words


Logo for the Certified Blockchain Professional.

As previously discussed, I'm doing the Certified Blockchain Professional course. It is self-directed learning, so I'm going through it at my own pace. In order to consolidate my learning, and help organise my thoughts, I'm blogging about my reflections on each module. These are mostly notes to myself - but I hope if you find something interesting (or incorrect) that you'll leave a comment. …

Why is there no formal specification for otpauth URls?

· 4 comments · 950 words · Viewed ~1,410 times


A QR code.

Yes yes, Cunningham's law etc etc! I want to play around with 2FA codes. So, I started looking for the specification. Turns out, there isn't one. Not really. IANA has a provisional registration - but no spec. It links to an archived Google Wiki which, as we'll come on to, isn't sufficient. There's some documentation from Yubico which is mostly a copy of the Google wiki with some incompatible…

My 2022 predictions from 2012

· 3 comments · 800 words · Viewed ~4,767 times


A tiny TARDIS made of Lego.

Exactly a decade ago, I asked "Why Can't Red Dwarf Predict The Future?" That is - sci-fi writers can imagine interstellar travel and sentient computers, but they think the future will still involve developing film photographs, library fines, and 3-pin electrical plugs. At the end of the post, I said: Here are my thoughts on some trivial aspects of our lives which - if put in a sci-fi film -…

How should user comments be marked up in HTML5?

· 5 comments · 900 words · Viewed ~317 times


The HTML5 Logo.

This is quite the epitome of yak-shaving! Suppose you have an article written in HTML. The basic layout might be something like: <body> <main> <article> The content of your article ... Pretty standard. Now suppose you let users add comments to the article. I have two questions: Where in the tree should they go? What HTML element should be used to group them? It…

Movie Review: Dave Made A Maze

· 2 comments · 200 words


Movie poster featuring lots of cardboard.

Well, this is an unexpected treat! What happens if you build a maze you can't get out of? How many people do you inadvertently drag in to your craziness? Are you responsible if they get hurt by the traps you set for yourself? Remember that 1990s horror movie "Cube"? This has exactly the same vibe. Except all the rooms are made of cardboard. And the deaths are… well, no spoilers - but funny. It …