Age specification, a simple file encryption tool & format

made by filippo, Benjojo, submitted by davidbalbert
Age is a replacement for GPG's file encryption features that will be easier to use without making mistakes.

Efficient Private Contact Search

made by gtank, filippo, submitted by wesleyac
An explanation of some of the difficulties in private information retrieval, along with an interesting scheme to make using bloom filters more tenable.

A Go implementation of Poly1305 that makes sense

made by filippo, submitted by porterjamesj
Filippo does great work trying to demystify cryptography and improve implementations of cryptographic algorithms, and this is a nice example.