For several years, CryptoHack has been a free platform for learning modern cryptography through fun and challenging programming puzzles. From toy ciphers to post-quantum cryptography, CryptoHack has a wide-ranging and ever increasing library of puzzles for both the aspiring and accomplished...

On April 19th 2022, Neil Madden disclosed a vulnerability in many popular Java runtimes and development kits. The vulnerability, dubbed "Psychic Signatures", lies in the cryptography for ECDSA signatures and allows an attacker to bypass signature checks entirely for these signatures. How are...

Threema is a Swiss encrypted messaging application. It has more than 10 million users and more than 7000 on-premise customers. Prominent users of Threema include the Swiss Government and the Swiss Army, as well as the current Chancellor of Germany, Olaf Scholz. Threema has been widely advertised...