We propose a new simple logic that can be used to specify , i.e. security properties that refer to a single participant of the protocol specification. Our technique allows a protocol designer to provide a formal specification of the desired security properties, and integrate it naturally into the design process of cryptographic protocols. Furthermore, the logic can be used for formal verification. We illustrate the utility of our technique by exposing new attacks on the well studied protocol TMN.
In this section we discuss some related work. In @cite_18 , Roscoe identifies two ways of specifying protocol security goals: firstly, using specifications, and secondly using specifications. An extensional specification describes the intended service provided by the protocol in terms of behavioural equivalence @cite_8 @cite_7 @cite_0 . On the other hand, an intensional specification describes the underlying mechanism of a procotol, in terms of states or events @cite_2 @cite_5 @cite_18 @cite_6 @cite_17 @cite_13 .
@cite_18 @cite_7 @cite_8 @cite_6 @cite_0 @cite_2 @cite_5 @cite_13 @cite_17
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A novel approach to malware detection by recognizing known inter-process and intra-process malicious functionalities in software behavior is proposed. It encompasses two essential tasks: the specification of a functionality that may involve a joint activity of several apparently independent processes, and efficient recognition of the specified functionality in the process behavior. The robustness of the proposed technology is achieved by the generalization of the specification domain that is separated from the detection domain. The functionalities of interest are defined in the abstract system domain through activity diagrams, thus resulting in formal specifications that are rather generic and less prone to false negatives. To facilitate the detection, we developed a procedure that automatically generates a Colored Petri Net recognizing the specified functionality in the system call domain. The separation of specification and recognition domains results in signature expressiveness and recognition efficiency. The approach is illustrated by the analysis, specification and consequent recognition of several common malicious functionalities including self-replication engines and popular payloads. A prototype IDS implementing the proposed approach has been developed and successfully tested on a set of real malware. When formalizing security protocols, different specification languages support very different reasoning methodologies, whose results are not directly or easily comparable. Therefore, establishing clear mappings among different frameworks is highly desirable, as it permits various methodologies to cooperate by interpreting theoretical and practical results of one system in another. In this paper, we examine the non-trivial relationship between two general verification frameworks: multiset rewriting (MSR) and a process algebra (PA) inspired to CCS and the π-calculus. Although defining a simple and general bijection between MSR and PA appears difficult, we show that the sublanguages needed to specify a large class of cryptographic protocols (immediate decryption protocols) admits an effective translation that is not only bijective and trace-preserving, but also induces a weak form of bisimulation across the two languages. In particular, the correspondence sketched in this abstract permits transferring several important trace-based properties such as secrecy and many forms of authentication. Since the 1980s, two approaches have been developed for analyzing security protocols. One of the approaches relies on a computational model that considers issues of complexity and probability. This approach captures a strong notion of security, guaranteed against all probabilistic polynomial-time attacks. The other approach relies on a symbolic model of protocol executions in which cryptographic primitives are treated as black boxes. Since the seminal work of Dolev and Yao, it has been realized that this latter approach enables significantly simpler and often automated proofs. However, the guarantees that it offers have been quite unclear. In this paper, we show that it is possible to obtain the best of both worlds: fully automated proofs and strong, clear security guarantees. Specifically, for the case of protocols that use signatures and asymmetric encryption, we establish that symbolic integrity and secrecy proofs are sound with respect to the computational model. The main new challenges concern secrecy properties for which we obtain the first soundness result for the case of active adversaries. Our proofs are carried out using Casrul, a fully automated tool. We present a formal model for modeling and reasoning about security protocols. Our model extends standard, inductive, trace-based, symbolic approaches with a formalization of physical properties of the environment, namely communication, location, and time. In particular, communication is subject to physical constraints, for example, message transmission takes time determined by the communication medium used and the distance traveled. All agents, including intruders, are subject to these constraints and this results in a distributed intruder with restricted, but more realistic, communication capabilities than the standard Dolev-Yao intruder. We have formalized our model in Isabelle HOL and used it to verify protocols for authenticated ranging, distance bounding, and broadcast authentication based on delayed key disclosure.