New Protocols Of Password-based Authentication Key Exchange

This paper puts forward some security claims on authenticated protocols combining with some new ideas of authentication theories, espesialy in password authentication.Combining with model of EKE and model of Shoup, we advance a new security model including ideal model and stander model, which hightlights a Testkm oracle. And it is the importence. With the test oracle, we put forward PAKO protocol. The oracle plays the role of a bridge for proving the security of the protocols, and our model can reflect an es-sential aspect of password authentication exchange protocols. These two protocols have difference in the first stage and the same in the second stage. PAKO is proved secure under ideal model while PAKS is proved secure under standard. We make these two protocols prove using a new method different from many other methods in related field.We propose an off-line attack on EKE protocol, when the underline space of the sub-group is much smaller than encrypt space, and this attack is very effective. The PAKS can defend this attack.Finally, we indicate that PAKO and PAKS cannot defend the attack after the server is compromised. So we advance PAKS-X protocol, which can defend this attack, and we in-troduce the integrity of PAKS-X. This protocol is an extension from the PAKS Protocol.