Strong notions of security for unconditionally secure digital signature schemes (USDS) were recently proposed where security is defined based on notions of security in computationally–secure digital signatures. The traditional area of unconditionally secure authentication, however, is that of “authentication codes” (A–codes). Relations between primitives is central to cryptographic research. To...

As traditional oblivious transfer protocols are treated as cryptographic primitives in most cases, they are usually executed without the consideration of possible attacks, e.g., impersonation, replaying, and man-in-the-middle attacks. Therefore, when these protocols are applied in certain applications, such as mental poker game playing and fairly contracts signing, some extra mechanisms must be...

The security guarantees provided by SSL/TLS depend on the correct authentication of servers through certificates signed by a trusted authority. However, as recent incidents have demonstrated, trust in these authorities is not well placed. Increasingly, certificate authorities (by coercion or compromise) have been creating forged certificates for a range of adversaries, allowing seemingly secure...

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The Exponential Challenge Response (XRC) and Dual Exponential Challenge Response (DCR) signature schemes are the building blocks of the HMQV protocol. We propose a complementary analysis of these schemes; on the basis of this analysis we show how impersonation and man in the middle attacks can be mounted against the HMQV protocol, when some session specific information leakages happen. We defin...

Ronald A. Gove 85.1 Some Basic Definitions....................................................... 1095 85.2 Some Historical Notes........................................................ 1096 85.3 The Basics of Modern Cryptography................................ 1098 85.4 Stream Ciphers.................................................................... 1099 85.5 Block Ciphers .....................

Man-in-the-Middle (MM) is not only a ubiquitous attack pattern in security, but also an important paradigm of network computation and economics. Recognizing ongoing MM-attacks is an important security task; modeling MM-interactions is an interesting task for semantics of computation. Traced monoidal categories are a natural framework for MM-modelling, as the trace structure provides a tool to h...

This paper presents a model for generating a MAC tag by injecting the input message directly into the internal state of a nonlinear filter generator. This model generalises a similar model for unkeyed hash functions proposed by Nakano et al. We develop a matrix representation for the accumulation phase of our model and use it to analyse the security of the model against man-in-the-middle forger...

Approaches against Phishing can be classified into modifications of the traditional PIN/TAN-authentication on the one hand and approaches that try to reduce the probability of a scammer being successful without changing the existing PIN/TAN-method on the other hand. We present a new approach, based on challenge-response-authentication. Since our proposal does not require any new hardware on the...

In 2003, Novikov and Kislev proposed a scheme for an authentication of the user from the remote autonomous object. Recently Yang et al. pointed out an evidence of man-in-middle attack. In this paper we show another evidence of man-in-middle-attack. We also pointed out that reflection attack can also be framed successfully on the scheme.