Generating digital signatures on mobile devices

With the explosion of the mobile communication market, more and more handheld devices act as clients in the Internet. People use these devices to purchase books, play games, receive emails, etc. For protecting privacies, such applications should integrate digital signature schemes. Since handheld devices have poor computational capabilities and limited battery life, traditional computation intensive digital signature protocols that are based on asymmetric cryptographic algorithms are not suitable for mobile devices. We propose a server based signature (SBS) scheme for mobile devices. Besides achieving the same security level of the traditional digital signature protocols, the SBS scheme also: 1) reduces the computation complexity on the mobile devices; 2) reduces the communication consumption between signer and verifier. Application results show that our scheme is very useful for mobile communication systems.