Simple and Efficient Contract Signing Protocol

TL;DR

This paper introduces a simple, efficient RSA-based contract signing protocol that guarantees fairness and security with minimal message exchanges and optional use of a trusted third party only when necessary.

Contribution

It presents a novel, lightweight contract signing protocol that ensures fairness and security with only three message exchanges and conditional use of a trusted third party.

Findings

Ensures fairness with minimal message exchanges

Uses offline TTP only if a party fails to sign

Provides a secure and efficient contract signing method

Abstract

In this paper, a new contract signing protocol is proposed based on the RSA signature scheme. The protocol will allow two parties to sign the same contract and then exchange their digital signatures. The protocol ensures fairness in that it offers parties greater security: either both parties receive each other's signatures or neither does. The protocol is based on offline Trusted Third Party (TTP) that will be brought into play only if one party fails to sign the contract. Otherwise, the TTP remains inactive. The protocol consists of only three messages that are exchanged between the two parties.