Goldwasser-Micali cryptosystem

The Goldwasser-Micali cryptosystem is an encryption method that secures individual bits of information by hiding them as the quadratic residue or non-residue property modulo a special composite number. It leverages the difficulty of solving certain number theory problems to ensure that ciphertexts reveal no information about the original bits without a secret key. Specifically, it encrypts each bit separately, making it suitable for privacy-preserving applications like secure voting or private data sharing. The system ensures that, even if someone intercepts the encrypted bits, they can't determine the original data unless they possess the secret key, ensuring strong confidentiality.