Post-Quantum Resistant Encryption in Appterix

The Kyber encryption in Appterix is ​​post-quantum resistant because it is based on a presumably NP-hard method, the lattice problem of learning with errors. This method is so difficult to understand that even quantum computers cannot solve it in an acceptable time.

Quantum computers could theoretically solve the lattice problem of learning with errors in an acceptable time using Shor's algorithm. Shor's algorithm uses quantum mechanics to reduce the complexity of the problem.

However, Kyber encryption is resistant to the Shor algorithm because it uses a sufficiently large grid size. The grid size is a measure of the complexity of the problem. The larger the grid size, the more difficult it is for quantum computers to solve the problem.

Kyber encryption is one of four schemes selected by the National Institute of Standards and Technology (NIST) as a post-quantum cryptography standard. The other three schemes are CRYSTALS-Dilithium, Falcon and SPHINCS+.