INTRODUCTION The future security of societies that depend increasingly on networks is contingent upon how our complex human and technical systems evolve. New network technologies including the Internet favour fragmentation into many loosely connected open and closed communities governed by many different principles. Network communities are subject to highly unpredictable emergent behaviours, ma...

We develop a theory of mechanism design when agents are able to interfere with each others’ communication channels. We develop a kind of revelation principle, the “Noninterference Principle” which permits representation of arbitrary mechanisms by direct ones. The incentives to interfere will depend on the mechanism chosen; interference thus constrains contractual design. For instance, authority...

Kish proposed a scheme to exchange keys between two parties under the concealment of thermal noise. We show that the theoretical model in the scheme implicitly assumes thermal equilibrium throughout the communication channel. This assumption, however, is invalid in real communication systems. A slight temperature difference in the channel, as demonstrated in the paper, will lead to security fai...

As of October 2001, the potential for use of infectious agents, such as anthrax, as weapons has been firmly established. It has been suggested that attacks on a nations' agriculture might be a preferred form of terrorism or economic disruption that would not have the attendant stigma of infecting and causing disease in humans. Highly pathogenic avian influenza virus is on every top ten list ava...

We all have a notion of privacy and understand that we trade some of it away in order to have normal social interactions and communal security. Networked computer systems are no different. The notion of privacy is running squarely against the need for security in an increasingly networked world. Is it possible to have secure systems that honor privacy? There are two basic ways to secure a netwo...

Human-machine identiication is an important problem in cryptography that has applications in network access, electronic commerce, and smart-card design. It is a hard problem largely because human users have a very limited capacity in memorizing secrets and in performing protocols. Therefore, in addition to the requirement that a human-machine identiication scheme must be provably secure, the sc...

In 2004, W. C. Ku and S. M. Chen proposed an efficient remote user authentication scheme using smart cards to solve the security problems of Chien et al.’s scheme. Recently, Hsu and Yoon et al. pointed out the security weaknesses of the Ku and Chen’s scheme Furthermore, Yoon et al. also proposed a new efficient remote user authentication scheme using smart cards. Yoon et al. also modified the p...