Digital signature with multiple signatories based on modified ElGamal Cryptosystem

摘要

El Gamal Digital Signature typically works between one signatory and one verifier. This scheme will not work in situations where there are two (2) or more signatories. This paper proposes a variant of the El Gamal Digital Signature Scheme that allows multiple signatories in a single signature by modifying the ElGamal Cryptosystem. The modification allowed multiple senders to encrypt a plaintext message into a ciphertext using multiple private keys. The provision also provided a scheme for a digital signature that allowed multiple signatories be tendered in a document in a single signature.