Technical dictionary
RSA
Public-key system based on factoring—broken by Shor’s algorithm at sufficient scale.
Definition
RSA is a classical public-key algorithm used historically for encryption, signatures, and TLS. Its security relies on the difficulty of factoring large integers.
Shor’s algorithm factors integers in quantum polynomial time, so RSA is not post-quantum. Migration paths include ML-KEM (key establishment) and ML-DSA/SLH-DSA (signatures).