In 1949, Shannon published the paper ”Communication theory of secrecy systems”. This constituted a foundational treatment and analysis of encryption systems. He transferred the methods of information theory, originally developed as a mathematical model for communication over ”noisy” channels to the setting of cryptosystems. We give a brief introduction into his most outstanding ideas, such as t...

We describe JFK, a new key exchange protocol, primarily designed for use in the IP Security Architecture. It is simple, efficient, and secure; we sketch a proof of the latter property. JFK also has a number of novel engineering parameters that permit a variety of trade-offs, most notably the ability to balance the need for perfect forward secrecy against susceptibility to denial-of-service atta...

Recently Lee et al. proposed an efficient verifier-based key agreement protocol for three parties without server’s public key. Lee et al. claimed the proposed protocol could resist various attacks and provide the perfect forward secrecy. However, in this paper, authors shall show that their protocol suffers from the impersonation attack. At the same time, authors shall propose an improved metho...

In [13] we proposed a (ρr, ρw)-adversarial wiretap channel model (AWTP) in which the adversary can adaptively choose to see a fraction ρr of the codeword sent over the channel, and modify a fraction ρw of the codeword by adding arbitrary noise values to them. In this paper we give the first efficient construction of a capacity achieving code family that provides perfect secrecy for this channel.

We investigate the ergodic secrecy capacity of a Multiple-Input Multiple-Output (MIMO) wire-tap channel, where the instantaneous Channel State Information (CSI) is available at both the legitimate receiver and the eavesdropper, but not at the source. We derive the perfectsecrecy capacity under a general ergodic fading process (with a continuous probability density function) and show that a circ...

It is known that a message can be transmitted safely against any wiretapper via a noisy channel without a secret key if the coding rate is less than the so-called secrecy capacity CS , which is usually smaller than the channel capacity C. In order to remove the loss C−CS , we propose a multiplex coding scheme with plural independent messages. In this paper, it is shown that the proposed multipl...

This paper considers the problem of perfectly secure communication on a modified version of Wyner’s wiretap channel II where both the main and wiretapper’s channels have some erasures. A secret message is to be encoded into n channel symbols and transmitted. The main channel is such that the legitimate receiver receives the transmitted codeword with exactly n− ν erasures, where the positions of...

This paper considers security analysis of a cross-realm client-to-client password-authenticated key exchange (C2C-PAKE) protocol with indirect communication structure that was proposed for secure email. The protocol does not need any public key infrastructure (PKI) and was designed to enable senders and recipients of emails to register at different mail servers. However, mail servers require sh...

A new applicable wiretap channel with separated side information is considered here which consist of a sender, a legitimate receiver and a wiretapper. In the considered scenario, the links from the transmitter to the legitimate receiver and the eavesdropper experience different conditions or channel states. So, the legitimate receiver and the wiretapper listen to the transmitted signal through ...

Most of the current security architectures for grid systems use conventional public key infrastructure (PKI) to authenticate grid members and to secure resource allocation to these members. Certificateless public-key cryptography (CL-PKC) has some attractive properties which seem to align well with the demands of grid computing. In this paper, we present a certificateless protocol for authentic...