Distributed certification application via a trusted dealer

Distributed certification via threshold cryptography is much more secure than other ways to protect certification authority (CA) 's private key, and can tolerate some intrusions. As the original system such as ITTC, etc. , is unsafe, inefficient and impracitcal in actual network environment, this paper brings up a new distributed certification scheme, which although it generates key shares concentratively, it updates key shares distributedly, and so, avoids single-point failure like ITYC. It not only enhances robustness with Feldman verification and SSL protocol, but can also change the threshold ( t, k ) flexibly and robustly, and so, is muc hmore practical. In this work, the authors implement the prototype system of the new scheme and test and analyze its performance.