In this paper we propose a quantum asymmetric-key cryptosystem, which does not rely on a computationally hard problem for security, but on uncertainty principles of quantum mechanics, thus obtaining security against a computationally unbounded adversary. We first propose a universally composable security criteria for quantum asymmetric-key cryptosystems by adapting the universally composable se...

Nowadays, security approaches and solutions for SOA focus mainly on messages and data, but they forget the code security (both service code and exchanged code). Moreover, some security aspects (e.g. validity, correctness...) are usually forgotten. We state that any security approach will be incomplete if the security of both data (messages) and code (service code) is not addressed in a general ...

Computer security is an old problem which has lost none of its relevance — as is evidenced by the annual Security issue of ;login:. The systems research community has increased its attention to security issues in recent years, as can be seen by an increasing number of security-related papers published in the mainstream systems conferences SOSP, OSDI, and USENIX. However, the focus is primarily ...

This chapter deals with the issues concerning e-mail communication security. We analyze the most popular security mechanisms and standards related to the e-mail communication and identify potential threats and vulnerabilities. The most significant drawback of all current approaches is the impossibility of keeping headers information authentic. This leads to possible impersonation attacks and pr...

Modern businesses operates in an emerging global information society. In this information society it is imperative for modern organizations to take the protection of their information resources seriously. This protection of information resources is to a large extent dependent on human co-operated behavior. This human factor is the weakest link in information security, and consists of two interr...

Network security manager are faced with a rapidly changing and complex threat environment due to the proliferation of sophisticated hacking tools. Field studies of network security managers show that they rely on ad hoc collections of log analyzers and custom tools to make sense of multiple sources of data from distributed sensors. The volume of log data exceeds the ability of network security ...

Context-based security is an approach for modeling adaptive security solutions based on the situation of use of the system. Security policies in this approach are not static as it used to be in traditional systems. The security actions to be taken are based on the knowledge of the combination of various factors such as the location of the user, the surroundings, time, temperature etc making the...

among the most important jewish encounters with other cultures and civilizations, the encounter with islamic culture was, in our view, the most important. this encounter was in some aspects like their encounter with the ancient civilization, but the impacts were more valuable and constructive. under islamic rule, the jews not only had a sense of security but also enjoyed a relatively satisfacto...

Going all the way back to early time-sharing systems we systems people regarded the users, and any code they wrote, as the mortal enemies of us and each other. We were like the police force in a violent slum. — Roger Needham Microsoft could have incorporated effective security measures as standard, but good sense prevailed. Security systems have a nasty habit of backfiring and there is no doubt...

Based on a concise domain analysis we develop a formal semantics of security protocols. Its main virtue is that it is a generic model, in the sense that it is parameterized over e.g. the intruder model. Further characteristics of the model are a straightforward handling of parallel execution of multiple protocols, locality of security claims, the binding of local constants to role instances, an...