A Threshold Key Escrow Scheme For Placing of Escrow Agent Flexibly andidentifying Cheaters Efficiently

摘要

The thesis proposes a threshold key escrow scheme based on elliptic curve cryptosystem which places the respective importance of escrow agents flexibly on the premise of preventing cheating of key escrow. Firstly, In order to fill up a deficiency that general escrow schemes do not take the respective importance of escrow agents into consideration, the paper proposes a threshold key escrow scheme based on elliptic curve cryptosystem which places the respective importance of escrow agents flexibly. The scheme analyses a condition that key can be recovered by the indispensable participation of one escrow agent. More types of schemes can be designed by the concrete cases of escrow agents. Moreover, stick to the point that how to avoid cheating for key escrow, the paper puts forward the question of KMC' cheating and its preventing method while it averts the cheating of users, escrow agents and government supervision agency.