Goldreich, Goldwasser, Halevi (GGH) public key cryptosystem, GGH digital signature algorithm, NTRU public key cryptosystem, and NTRU signature scheme
Esra Bas · 2024
This chapter covers Goldreich, Goldwasser, Halevi (GGH) public cryptosystem, GGH digital signature algorithm, NTRU public key cryptosystem (NTRUEncrypt), NTRU signature scheme (NSS), and their cryptanalysis. The GGH public key cryptosystem is a lattice-based cryptography in which the “good basis” of the lattice is used as the private decryption key, while the “bad basis” of the lattice is used as the public encryption key. The GGH public key cryptosystem has been adapted to the GGH digital signature algorithm, in which the “good basis” of the lattice corresponds to the private signing key, while the “bad basis” of the lattice corresponds to the public verification key. Regarding the cryptanalysis of the GGH public key cryptosystem, some basic flaws of the GGH public key cryptosystem are explained, while the literature regarding some improvement suggestions is also mentioned. All public key cryptosystems and digital signature algorithms presented in this chapter are illustrated with examples.