alt Hacker NewsBut in all fairness it seems like a reasonable system, given the narrow scope of its goals. It does not scale, but that's on purpose. Although I could still see "Feed Aggregation" becoming impractical even with a small number of friends with a modest number of posts.
Cryptographically, a problem is that it makes ciphertexts publicly enumerable, protected by a X25519-derived key. This makes it very vulnerable to harvest-now-decrypt-later attacks, if you believe quantum computing will ever happen.
> if you believe quantum computing will ever happen.
... and you don't believe that everything will be totally fucked when it does happen.
If there is a global passive observer, and they get quantum computing, a huge amount of supposedly encrypted private information just got popped. Whether or not I care about my dinky little private social network posts when every ssl/tls connection I've ever made is being cracked and data mined is an interesting question.