Good Xplanations

Privacy matters – Difference between TEE, ZK, MPC and FHE Everyone is talking about Privacy on-chain these days, and a lot of cryptographic terms are discussed. As co-inventor of ZK STARKs (post-quantum secure ZK systems) I’ll explain these technologies, what they’re good for, and their limitations. This is a long explanation, so today we'll start with TEE: TEE stands for Trusted Execution Environment. I think of TEE as an attempt to solve the problems of Privacy and Integrity, but they have a serious Trust problem. Let's dive in 🤿 TEE - what is it exactly? - A TEE is like a computer that’s hidden inside an enclave (a place that no one can look into). - You send it information using a public key system, meaning everyone can send it encrypted data - Then, it can decrypt that data, process it with integrity, encrypt it back, sign it for integrity, and send it back to you (in encrypted form). In theory, it’s a bit like having a direct encrypted line to God, or to some trustworthy machine, and you ask it what to compute, and it does that without leaking any information, hence, you get privacy. The problem: This holds only in theory. Why? The mentioned enclave is a physical chip that sits inside a computer. Whoever is in possession of that computer and running it can mess around with the TEE and get it to leak information it's not supposed to. So the privacy you’re guaranteed by the brochures isn’t as tight as you’d think. The bigger problem: (aka the problem that implies you should never trust a TEE for running a truly decentralized blockchain) For a certain amount of $ someone (think Lazarus group) can extract the keys that a TEE uses to (a) decrypt your messages and (b) sign on the integrity of the computation it performs. Once the bad guys have this key, they can sign on *any* payload and also read your messages. It’s unlikely they’ll do this from afar to the TEE on your smartphone or laptop, which is why you can use it for your own wallet and for small sums. But, and this is the important part, you cannot have a consensus system relying on TEE for trust. So: TEEs can be used on end-user devices for securing small amounts of money, and they are OK as security theater, when there’s a central operator that you rely on (but in this case the system is better off acknowledging there’s a central party running it, and that it's not decentralized). TEEs cannot serve truly decentralized blockchains. Next time: ZK The END

Bitcoin is insurance against fiat. ZCash is insurance against Bitcoin.

Bitcoin is insurance against fiat. ZCash is insurance against Bitcoin.

Tachyon consolidates the entire Zerocash protocol into a single distributed key-value store with an append-only log of test-and-set operations using recursive SNARKs. Almost everything is stripped from a txn before it is recorded, and *all* that remains is pruned.

CZ pleaded guilty to a criminal money laundering charge and was sentenced to prison. But then he financed President Trump’s stablecoin and lobbied for a pardon. Today, he got it. If Congress does not stop this kind of corruption, it owns it.

when i started building echo 2 years ago, i knew it had 95% chance of failing. to be honest, i couldnt really imagine any other outcome, but i thought at least it may be a noble failure worth attempting. i certainly didn't think echo would be sold to coinbase, but, here we are: today coinbase bought echo for ~$375m. echo will remain a standalone platform under its current brand for now, but we will integrate sonar's public sale product into coinbase, and likely introduce new ways for founders to access investors, and for investors to access opportunities into coinbase itself. over the years i have chatted to brian a handful of times, and mostly to complain at him honestly. i have always respected how brian would listen to an outsider chat shit at him on the phone and take the feedback seriously. now, instead of complaining, i will have the opportunity try to do the work to make things better. crypto itself has moved on a long way since we started working on echo. i guess partially this is because of the election result. but, i feel energised by a lot of the cool things being built in crypto again: hyperliquid, zcash, stablecoin supercyle, and so on. feels like a good time to be on the field instead of an idiot with a twitter account yapping nonsense. well, i guess i still will be that. anyway, job's not finished. onwards. oh fuck yeah, before i go, the final season of up only (now "unc only" due to our severe old age) will commence when we figure out who the guests should be lol cobber