Providing High Availability to Time-Stamping Services Using Threshold Signature

We present a solution to the high availability issue that arises when digital time-stamping authority tries providing robust services to its users. High availability of time-stamping services is very important because any suspension of service due to system failure or potential attacks results in serious monetary losses. In this paper, we present a new approach that deploys an RSA threshold signature scheme to offer high availability for multiple time-stamping servers. It allows the sharing of signing key into n servers while the robustness of the system is unaffected even if some subsets of less than t servers are corrupted and work together. Our proposed solution provides a strong prevention measure instead of recovery measure of physical operation and cryptographical attack. Thus, it enjoys a higher level of security protection than traditional high availability protocol.