Provably Leakage-Resilient Password-Based Authenticated Key Exchange

During the past two decades,side-channel attacks have become a familiar method of attacking cryptographic systems,which allow an attacker to learn partial information about the internal secrets such as the secret key.For example,in the Internet of things,the mobile Internet or the Ad Hoc network,most nodes are very vulnerable to side-channel attacks because they are exploded in the public environments.A scheme that is secure in the traditional model will be vulnerable in the leakage environments,because traditional model suppose that calculations are secretly computed and there hasn't any leakage attack.Thus designing a strong,meaningful,and achievable security scheme to capture the practical leakage attacks is one of the primary goals of leakage-resilient cryptography.In this paper,we have studied provably leakage-resilient password-based authenticated key exchange and first proposed a Leakage-Resilient three-party Password-based Authenticated Key Exchange(LR 3PAKE)protocol and a Leakage-Resilient Group Password-based Authenticated Key Exchange(LR GPAKE)protocol.3PAKE protocol is an important practical cryptographic primitive in the client-client communication environments,where two clients could generate a shared secure session key using their human-memorable passwords with a server's help.In this paper,we first define a ?-CAFLR eCK security model for 3PAKE by extending the only computation leakage model properly,which can not only describe the traditional security attack methods(eavesdropping,tampering,replay attack,impersonation attack,off-line dictionary attack,non-detectable online dictionary attack,etc.)and can also capture leakage attacks.In the model,the leakages are continuous and are allowed even after the adversary selects the test session,and the whole leakage size may be infinitely large,and for each protocol instance the amount of leakage is bounded by ?.Then,we propose a LR 3PAKE protocol based on key derivation function,leakage-resilient storage and leak-age-resilient refreshing of LRS,we show a formal security proof in the standard model based on the new CAFLR eCK security model.Group password-based authenticated key exchange protocol provides n parties who hold a common human-memorable password for secure group communication.Secure group communication is an important research area in the field of cryptography and network security,because the group communication like electronic conferences,video chatting,video games etc.are rapidly increasing.In this paper,we first define a ?-CAFLR eCK security model for GPAKE by extending our LR 3PAKE security model properly,Then,we propose the first LR GPAKE protocol by combining DH GKE protocol and Dziembowski-Faust LRS scheme appropriately.we formally prove the CAFLR eCK security in the standard model based on the game simulation techniques.