Journal of Mathematics Research; Vol. 11, No. 6; December 2019 ISSN 1916-9795 E-ISSN 1916-9809 Published by Canadian Center of Science and Education Provable Security of The Generalized ElGamal Signature Scheme Demba Sow1 & Mamadou Ghouraissiou Camara2 1 Faculte´ des Sciences et Techniques, Departement´ de Mathematiques´ et Informatique, Universite´ Cheikh Anta Diop de Dakar, Sen´ egal´ 2 Institut Superieur´ de Technologie de Mamou (ISTM), Departement´ de Genie´ Informatique, Republic of Guinea Correspondence: Demba Sow, Faculte´ des Sciences et Techniques, Departement´ de Mathematiques´ et Informatique, Uni- versite´ Cheikh Anta Diop de Dakar, Sen´ egal.´ Tel: 00221776084855. E-mail:
[email protected] Received: October 23, 2019 Accepted: November 15, 2019 Online Published: November 19, 2019 doi:10.5539/jmr.v11n6p77 URL: https://doi.org/10.5539/jmr.v11n6p77 Abstract A new variant of the ElGamal signature scheme called ”a Generalized ElGamal signature scheme” is proposed in 2011. The Generalized ElGamal signature scheme is a modified ElGamal signature scheme. In this paper, we propose the security proof of the Generalized ElGamal signature scheme in the random oracle model. First, we recall some security notions of signature schemes and show the security of the modified ElGamal Signature scheme. Keywords: signature scheme, ElGamal, DSA signature, provable security 1. Introduction Digital signatures perform an important role in verifying the identity of a sender of a document. A digital signature is represented as a string of binary digits. The signature is a process using a set of rules and parameters (algorithm) to ensure the identity of the sender of a document and the originality of the data.