Biblio

A multi-designated receiver authentication code (MDRA-code) with information-theoretic security is proposed as an extension of the traditional multi-receiver authentication code. The purpose of the MDRA-code is to securely transmit a message via a broadcast channel from a single sender to an arbitrary subset of multiple receivers that have been designated by the sender, and only the receivers in the subset (i.e., not all receivers) should accept the message if an adversary is absent. This paper proposes a model and security formalization of MDRA-codes, and provides constructions of MDRA-codes.

Considering application to communication among wireless sensors, Ma and Tsudik introduced the notion of forward-secure sequential aggregate (FssAgg) authentication in 2007. They also proposed an FssAgg MAC scheme composed of a MAC function and cryptographic hash functions at the same time. The security of their proposed scheme has not been analyzed yet and remains open. It is shown in this paper that a slight variant of the Ma-Tsudik FssAgg MAC scheme is secure under reasonable and standard assumptions on security of the underlying primitives. An efficient instantiation of the underlying MAC function using a cryptographic hash function is also discussed.

The malicious JavaScript is a common springboard for attackers to launch several types of network attacks, such as Drive-by-Download and malicious PDF delivery attack. In order to elude detection of signature matching, malicious JavaScript is often packed (so-called "obfuscation") with diversified algorithms therefore the occurrence of obfuscation is always a good pointer for potential maliciousness. In this investigation, we propose a light weight approach for quickly filtering obfuscated JavaScript by a novel method of tokenizing JavaScript text at letter level and information-theoretic measures, based on the previous work in the domain of detecting obfuscated malicious code as well as the pattern analysis of natural languages. The new approach is apparently time efficient compared to existing systems since it processes much less objects while it is also proved to be able to reach the acceptable detection accuracies.