Pointcheval–Stern signature algorithm

In cryptography, the Pointcheval-Stern signature algortihm is a digital signature scheme based on the closely related ElGamal scheme. It changes the ElGamal scheme slightly to produce an algorithm which has been proven secure agaisnt adaptive chosen-message attacks. that is, if the discrete-logarithm problem is intractivle in a strong sense. (see D Pointcheval and J Stern. Security proofs for signature schemes. in U Maurer, ed. Adv in Crypt -- Eurocrypt '96, 387-398, Springer-Verlag, 1996. Lect Notes in ComP Sci, nr 1070); and D Pointcheval and J Stern, Security arguments for digital signatures and blind signatures, J Crypt 13(3):361-396, 2000.)

David Pointcheval and Jacques Stern developed the forking lemma technique in contructing thier proof for this algorithm. it has been used in other security investigations for other cryptographic algorithms.