Research On Authentication Key Establishment Protocols Under Mobile Client-Multi-Server Environment

With the rapid development of e-commerce,network service providers usually provide users with a wide range of services which run on different servers.Thus,multi-server model has been widely existed.On the other hand,more and more people start to quickly access network services through their mobile phones or other mobile devices.This is the mobile client-multi-server model that has been widely used by users.Mobile devices bring convenience to our lives.However,the openness of mobile Internet makes it's security issues more and more serious.It is necessary to design an authentication key agreement protocol for the mobile client-multi-server model.Mobile devices have lower performance compared to personal computers.Therefore,to design a protocol that combines security and efficiency is not an easy thing.In order to solve this problem,we studied the authentication key establishment protocol in the mobile client-multi-server model in this thesis.Certificateless public key cryptography does not need expensive digital certificates in the public key infrastructure.And it avoids the inherent key escrow problem in identity-based public key cryptography.Therefore,the certificateless public key cryptography is well suited for designing a security protocol for mobile devices which have limited resource.The main work of our thesis includes:(1)We first proposed a certificateless authentication key agreement protocol which was suitable for mobile client-multi-server model.Then,we proved that this protocol can provide mutual authentication and key agreement in the random oracle model.We also compared it with other protocols of the same type,and we analyzed it from three aspects: security,communication cost and computing cost.Finally,we implemented this protocol using JPBC library.(2)We proposed another more efficient protocol for mobile devices which have low performance in computing.This protocol does not use time-consuming operation of bilinear pairing,which greatly reduced the computational consumption.In comparison with other protocols of the same type,this protocol has a very significant advantage in computational efficiency.Similarly,we implemented this protocol using JPBC library,and we analyzed it from three aspects: security,communication cost and computing cost.(3)We developed a secure communication system based on our protocols.Thissystem consists of mobile client,application server and registration server,and it realized the secure communication process in multi-server environment,which proved that the protocols proposed in this paper are practical.