> no-one will know who decrypted it > Every node receives every message. Neither one of these strike me as desirable characteristics of a secure messaging sys

> no-one will know who decrypted it > Every node receives every message. Neither one of these strike me as desirable characteristics of a secure messaging system. I can see the advantage in a third party not being able to tell who received a message, but in a perfect world as the sender I'd like to know that only my intended recipient received it, which is the opposite of what's going to happen with the block chain. Also, to encrypt with AES you need to pick a key length, and since your message is going to everyone in the world, you need to pick a key that is both impractical to break using today's technology, but using all future technology for as long as your secret remains relevant. If AES is ever broken, then all bets are off. If you have a chance to exchange keys of unlimited length ahead of time, then you could use a one time pad and message over the block chain. This would be secure, but then if you have a OTP, almost any message channel you pick is going to be secure. Someone else in this conversation recommended using newspaper ads.