Threshold signature schemes for ElGamal variants

In this paper we present a generic construction of threshold ElGamal signature schemes. We classify ElGamal variants by two types according to ways of generating signatures. Then we develop the generic mechanism to convert a group of ElGamal variants into their threshold versions and prove unforgeability of constructed schemes. To demonstrate its application, we present threshold versions of two standard ElGamal variants, GOST 34.10 and KCDSA from our construction.