An asymmetric cipher based on the difficulty of factoring large semiprimes. Supports key generation, encryption, and decryption.

The finite-field discrete-log ancestor of ECDSA (NIST FIPS 186, 1994) — same r/s signature equation, computed in a prime-order subgroup instead of on a curve. Demo uses toy parameters; real DSA needs p>=2048 bits, q>=224 bits.

A key exchange protocol enabling two parties to establish a shared secret over an insecure channel.