Sains Malaysiana 35(2): 69-72 (2006)                          

A New Version of ElGamal Signature Scheme

(Versi Baru Skema Tandatangan ElGamal)

Eddie Shahril Ismail

Pusat Pengajian Sains Matematik, Fakulti Sains & Teknologi

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E

Yahya Abu Hasan

Pusat Pengajian Sains Matematik

Universiti Sains Malaysia

11800 USM Minden, Penang

ABSTRACT

In the original ElGamal signature scheme and it’s variants, two secret integers-private key and one-time secret key are required to produce a signature on a message, m. The private key of a system will be used throughout the life of the system whereas the one-time secret key only be used once and must be regenerated (different one-time secret key) when signing different message. This paper introduces a new version of ElGamal signature that eliminates the use of one-time secret key. This property will make all attacks, aiming at revealing the one-time secret key irrelevant. The scheme also can be regarded as ‘a right notion of signature scheme’ because we use only one secret key to sign messages. 

Keywords: cryptography; ElGamal signature scheme;  discrete logarithm problem

ABSTRAK

Dalam tandatangan ElGamal asal dan versi-versinya, dua integer sulit-kunci rahsia dan kunci sulit satu-masa diperlukan untuk menurunkan tandatangan pada suatu mesej, m. Kunci rahsia akan diguna sepanjang hayat sistem itu manakala kunci sulit satu-masa hanya diguna sekali dan mesti dijana semula (kunci sulit satu-masa yang baru) apabila menandatangani mesej seterusnya. Kertas ini memperkenal versi baru tandatangan ElGamal yang menghapuskan penggunaan kunci sulit satu-masa. Melalui ciri ini, semua serangan yang bertujuan mendedahkan kunci sulit satu-masa menjadi tidak lagi relevan. Sistem ini boleh dianggap sebagai ‘skema tandatangan yang tepat’ kerana memerlukan hanya satu kunci rahsia untuk menanda tangan mesej-mesej. 

Katakunci: kriptografi; skema tandatangan ElGamal; masalah logaritma diskret

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