Elliptic Curve, Diffie Hellman, Discrete Log, Elgamal Encryption.
chooses a number y such that 2≤y≤p-2. Bob then calculates nonzero residue of g^y (mod p) calling it r. To encrypt the message, Bob calculates c which is m*h^y modulo p. Bob sends r and c to Alice. Alice, so as to decrypt the message, computes c*r^-x mod p, which is actually