Efficient and leakage-resilient authenticated key transport protocol based on RSA

Let us consider the following situation: (1) a client, who communicates with a variety of servers, remembers only one password and has insecure devices with very-restricted computing power and built-in memory capacity; (2) the counterpart servers have enormous computing power, but they are not perfectly secure; (3) neither PKI (Public Key Infrastructures) nor TRM (Tamper-Resistant Modules) is available. Our main goal of this paper is to provide its security against the leakage of stored secrets as well as to attain high efficiency on client's side. For those, we propose an efficient and leakage-resilient RSA-based Authenticated Key Establishment (RSA-AKE) protocol suitable for the above situation whose authenticity is based on password and an additional stored secret. The RSA-AKE protocol is provably secure in the random oracle model where an adversary is given the stored secret of client and the RSA private key of server. In terms of computation costs, the client is required to compute only one modular exponentiation with an exponent e (e >= 3) in the protocol execution. We also show that the RSA-AKE protocol has several security properties and efficiency over the previous ones of their kinds.