A Directed Signature Scheme Based On Discrete Logarithm Problem

Abstract

Kertas ini membangunkan skema baru tandatangan directed yang berdasarkan masalah logaritma diskret, suatu skema yang membenarkan hanya pengesah yang layak untuk mengesah tandatangan. Skema ini juga berupaya membuktikan kepada pihak ketiga keaslian tandatangan. Skema baru ini juga mencapai tahap keselamatan yang setara tetapi lebih efisien berbanding dengan skema Lim–Lee. Dua aplikasi langsung dibincangkan: pengesahan perkongsian fleksibel dan prosedur tandatangan kontrak cetusan daripada skema tandatangan directed yang baru. Kata kunci: Kriptografi; tandatangan digital; tandatangan directed; masalah logaritma diskret; teknik zero–knowledge This paper presents a new directed signature scheme based on discrete logarithm problem, a scheme that permits only an intended verifier to verify a resulting signature. In addition, the scheme is able to prove to any third party the validity of the signature. Essentially, we illustrate that the scheme achieves the same level of security but is very efficient compared to Lim–Lee’s scheme. Two immediate applications are also presented: flexible shared verification and signing contracts procedure extended from the new directed signature scheme. Key words: Cryptography; digital signature; directed signature; discrete logarithm problem; zeroknowledge technique