Concise Christmas Cryptography Challenges 2019

What this post added

This post presents a series of cryptography challenges from 2019, including a TLS Client Hello analysis, a Time-Based One-Time Password (TOTP) vulnerability, and an RPKI-based message decoding challenge. The solutions reveal insights into encrypted SNI, a flawed TOTP implementation lacking a shared secret, and the use of RPKI ROAs to hide messages. The post also includes hints and solutions for each challenge, demonstrating practical applications of cryptographic concepts.