The S-boxes used in DES were carefully tuned for resistance against differential cryptanalysis, a technique not known to the public at that time but known to designers of DES. It was later discovered that even a small change to DES would make it more susceptible to differential cryptanalysis. My ...

Out of sheer curiosity, I've been referring to RFC 8446 and implementing a TLS 1.3 client. I've implemented traffic key derivation as described in section 7.1 of the RFC. There is a note in the last paragraph of section 7.1 (page 91) (https://datatracker.ietf.org/doc/html/rfc8446#section-7.1) sta...