Reliability and Key-Protection for Computer-Security Systems

The threshold scheme is an approach to ease the trade-off between the master-key protection and system reliability in computer security systems where the encryption method is implemented. This paper proposes a model to investigate the quantitative relationship among key protection, key recovery, and threshold selection. An algorithm based on this relationship is developed to select an appropriate threshold against the design goal. The numerical simulation recommends that the threshold parameters in a trusted environment can be smaller, while those must be larger and close to each other in a hostile environment to overcome its defect.