[Resource Topic] 2021/148: On methods of shortening ElGamal-type signatures

Welcome to the resource topic for 2021/148

On methods of shortening ElGamal-type signatures

Authors: Liliya Akhmetzyanova, Evgeny Alekseev, Alexandra Babueva, Stanislav Smyshlyaev


Development of signature schemes providing short signatures is a quite relevant non-trivial challenge for cryptographers. Since the late 1980’s many short signature schemes have been proposed. The most perspective schemes are multivariate schemes and schemes based on Weil pairing. Unfortunately, the cryptographic tools used in these schemes are still not supported by most cryptographic software that complicates their effortless use in practice. In the current paper we investigate the opportunity of shortening the standard ElGamal-type signatures. We propose three methods of shortening signatures (for any ElGamal-type schemes such as ECDSA, GOST and SM2) and analyze how applying these methods affects the security. Applying all three methods to the GOST signature scheme with elliptic curve subgroup order q, 2^{255} < q < 2^{256}, can reduce the signature size from 512 to 320 bits. The modified scheme provides sufficient security and acceptable (for non-interactive protocols) signing and verifying time.

ePrint: https://eprint.iacr.org/2021/148

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .