Contract signature in e-commerce

In this paper, we propose a notion of contract signature used in e-commerce applications. We propose a contract signature scheme based on the discrete logarithm assumption. The contract signature scheme adopts a digital multi-signature scheme in public-key cryptography to facilitate fair signature exchange over network. This proposed solution allows multiple signers of a contract signature to exchange their partial signatures which are fully ambiguous for any third party (i.e., 1 out of ∞ ambiguity) to construct a valid contract signature. In case any signer releases the partial signature to others, the signer does not bind to the contract.