Zahra Rajaei Rizi - Computer and IT department Sheikh-Bahaei University Isfahan, Iran
Mehdi Salimian Rizi - IT department Amirkabir University Tehran, Iran

Mobile commerce is becoming more popular every day. It brings convenience and flexibility to users. However, some factors do not let m-commerce to be fully accepted. Security is always a big challenge. Non-repudiation is a security service, maintaining cryptographic evidence in electronic transactions. Providing this service is a bit difficult because of limited resources of mobile devices. The main contribution of this paper is to introduce a lightweight protocol that guarantees non-repudiation for the constrained platforms such as mobile phones. We develop a novel idea that does not use digital signature and even symmetric cryptography, instead, we use hash functions and secret splitting and employ a semi-trusted third party, reducing computation costs and computational overheads, and adapting to the constraints in mobile devices

mobile commerce; non-repudiation; Security; cryptography