Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

The original version of this story appeared in Quanta Magazine. Hard problems are usually not a welcome sight. But cryptographers love them. That’s because certain hard math problems underpin the ...

Hard problems are usually not a welcome sight. But cryptographers love them. That’s because certain hard math problems underpin the security of modern encryption. Any clever trick for solving them ...

Update: On 18 April, Yilei Chen announced an issue with his algorithm which he does not know how to fix. This means the algorithm does not undermine the mathematics behind post-quantum cryptography.