In
cryptography
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), ...
, the Pointcheval–Stern signature algorithm is a
digital signature scheme based on the closely related
ElGamal signature scheme. It changes the ElGamal scheme slightly to produce an algorithm which has been proven secure in a strong sense against
adaptive chosen-message attacks, assuming the
discrete logarithm problem is intractable in a strong sense.
David Pointcheval and
Jacques Stern developed the ''
forking lemma'' technique in constructing their proof for this algorithm. It has been used in other security investigations of various cryptographic algorithms.
References
Digital signature schemes
Public-key cryptography
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