on timeliness of a fair non-repudiation protocol
In 1996, J. Zhou and D. Gollmann proposed a fair non-repudiation protocol, which was unfair in fact for its lack of timeliness. K. Kim, S. Park and J. Baek improved it by adding time limit information to protocol messages. However, the improvement needs mechanisms to synchronize clocks among the protocol entities, thus making its implementation inefficient. In this paper, to make Zhou-Gollmann's non-repudiation protocol provide timeliness while preserving its efficiency, a more efficient synchronization scheme was introduced to improve it. SVO logic was extended slightly to analyze the timeliness of the new protocol. The analysis result shows that while the original protocol does not provide timeliness, the newly updated one does.
timeliness fairness non-repudiation svo logic clock synchronization