Does Secure Password-Based Authenticated Key Exchange against Leakage of Internal States Exist?

Kazuki YONEYAMA 

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences  Vol.E92-A  No.1  pp.113-121
Publication Date: 2009/01/01
Online ISSN: 1745-1337
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Secure Protocol
Keyword: 
authenticated key exchange,  password,  leakage of static key,  leakage of ephemeral key,  3-party setting, 

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Summary: 
In this paper, we raise a question about existence of secure password-based authenticated key exchange against leakage of internal states (i.e., the passwords and session-specific private information). Toward this question, first, we classify six models of adversary's capabilities about leakage. Next, as a result of considerations for 2-party PAKE, we find two negative answers, but also find a positive answer. More specifically, we show that there exists no scheme which is secure in strong leakage models, but we also show that there exists a scheme which is secure in weak leakage models. Also, we consider the case of 3-party setting which is a special setting of password-based authenticated key exchange, and we find similar impossibilities as 2-party setting.