http://qvt3o2ipzxx3gtoyafd3ptqwsxjs52enlwlxuryn2xjkm7hnp5icd6yd.onion/coyim/whats-new-v04/introduction/2022/02/13/whats-new-in-v04-improved-security.html
The process of writing
comprehensive tests really help think through what code is supposed to do. And while we didn’t find any actual security
issues, we did improve the code in many places, and making sure that our tests check that it’s doing what it’s supposed
to be doing.