Privacy, privacy, privacy: Everyone now is a Privacy expert. Great! So... Let me explain a few things, as someone who's spent quite a lot of time thinking about privacy, and building stuff that's actually used in the world (not just in tweets or academic papers 🙂). There are all kinds of privacy, and they don't all look the same, feel the same, or work the same. Here's an explanation on what's easy, what's hard, and what's the right way to get privacy done. What's easy: Creating ZK proofs for various transactions is easy (thank you StarkWare). You can't yet create ZK proofs on standard hardware wallets, but you can create them on phones and laptops and desktops. Important: Generating a ZK proof, or a bunch of them, doesn't mean yet you have *real* privacy. For that, you need more, and you need everyone to use what you've built, because if you're the only one using it, you get no privacy. What's (really really really) hard: UX. Achieving privacy with UX that will be smooth and intuitive enough to make it easy for you, me, your mom, and your friends to use is really really really hard . In the tradfi world that's really easy, because the model is different: Your tradfi buddy (the bank, typically) opens an encrypted channel with you, and you tell it privately everything, and the bank keeps that stuff secret. But in the decentralized world you don't have a buddy you can whisper secrets to. So if you want privacy, you need everything to be built for that. And here's the problem: The existing infra of blockchain is not privacy-compatible. Starting with Bitcoin, it's all out there in the open. This means that the standards and the tools and the wallets and the exchanges are all built for stuff that everyone sees. If you're building something that's private, it means that all the existing infrastructure stops working. No hardware wallets, with hard time getting exchanges to work with it, no block explorers, etc. It becomes really hard for your mom and friends to use it. So no one uses it, and the few who do use it, don't get much privacy. You've made it this far! You get a prize: The solution 🗝️ So what can be done? The truth is that the best path forward on privacy is to compromise a bit. Meaning, that in order to offer good UX, the privacy you'll get won't be airtight. So you'll get a certain level of privacy, it won't be airtight, but it'll be easier to use for your mom and friends. There are quite a few solutions that offer tradeoffs between privacy and usability, and many of them exist today, first and best on Starknet/StarkWare. I'll give a few examples: * Validium - is a way to build things that are 100% smooth and standard from the users point of view, but the stuff that goes on the blockchain is known only to your buddy (the operator, like the bank). As opposed to the bank, your buddy -- the operator -- in this case, cannot steal your money because ZK STARK proofs bind him to operate with integrity. * shielded ERC20s - these are account based, not UTXO based, and only blind the amounts being sent around, not the payer and payee. So folks can see who you're sending to and receiving from, but no one knows how much you're sending. It's not as airtight as a Zcash transaction, but it allows for smoother UX, and even allows you easy composability with a lot of DeFi apps. Summarizing: Privacy is needed. Creating ZK is by now not the hard part. The hard part is getting your mom and friends to be able to transact privately and smoothly on the blockchain. We're not there yet. But stay tuned. The END