Learn Me a Threat

I'm Zach. I just graduated grad school with a Master's degree in Physics, where I spent the last few years studying how quantum computers threaten Bitcoin. Along the way, I picked up a decent sense of how quantum computers affect other cryptocurrencies too.

I kind of stumbled into this. I started my Master's mostly because quantum computing was hyped up at the time and I was curious about it after some exposure to it in undergrad research. When it came time to pick a thesis topic, I landed on quantum attacks against Bitcoin for two reasons. First, it's a direct application of quantum computing that anyone can actually understand, not some esoteric thing only other physicists would get the point of. Also, crypto and NFTs were huge at the time, like Bored Ape NFTs selling for millions of dollars, so that definitely played into it.

I knew basically nothing about crypto or Bitcoin going in, but the more I read the more I got hooked on one specific thing about it. You're sending money back and forth to total strangers, with no bank in the middle and nobody you can call if something goes wrong. You'd think that shouldn't work at all, since nobody in it trusts anybody. It does work though, because the trust is created artificially, from nothing but math. I thought that was super interesting, and it's basically what turned into my thesis, which turned into a paper that's on arXiv now and in the process of getting published.

Honestly, I really like yapping about this stuff, and now that I'm done with school I don't have an outlet for that anymore. I find the topic interesting and I like teaching it. Some of my fondest memories from grad school are from teaching, as long as it was on something I actually cared about. This blog is meant to bring that feeling back.

So think of this blog as a museum of my thoughts while they're still fresh. If you want to follow along and find it interesting, that's a nice bonus. I do think it's useful on its own, though. How quantum computers affect cryptocurrencies and blockchains is a broader topic than most people expect, and the information is scattered across a pile of papers and reports. I want to put as much of it in one place as I can. I won't cover every attack or edge case, since there are too many, but I want to give a real lay of the land: how each attack works, what people think about it, and what could be (or is being) done.

You don't need any prior knowledge of Bitcoin, cryptography, or quantum computing. My goal is to make this accessible to anyone, explaining things rigorously from the ground up, in as plain language as I can manage.

This blog, and its name, are inspired by learnmeabitcoin.com by Greg Walker. It does a great job explaining how Bitcoin works in plain language. I won't go nearly as deep into Bitcoin's mechanics here because that's not really the point. If that's what you're after, go check out Greg's site.

Last thing, a disclaimer. I dislike writing and I'm slow at it, which I know sounds a bit paradoxical for someone writing a blog. I like this stuff more than I dislike writing about it, though, so writing is just the tax I pay to get it out of my head. I use AI (mainly Claude) to help with that part. I write out my raw thoughts and ideas, then use AI to help with structure, clarity, and flow, and I check accuracy along the way. The ideas, rigor, and explanations are mine, but parts of this blog are AI-assisted. If that's a dealbreaker, no hard feelings.