Sequences Of Message Exchanges Research Articles

Implementing Security Protocol Monitors

Cryptographic protocols are often specified by narrations, i.e., finite sequences of message exchanges that show the intended execution of the protocol. Another use of narrations is to describe attacks. We propose in this paper to compile, when possible, attack describing narrations into a set of tests that honest participants can perform to exclude these executions. These tests can be implemented in monitors to protect existing implementations from rogue behaviour.

Authentication Schemes for Open Distributed Network: A Classification

An authentication protocol is a sequence of message exchanges between entities that either distributes secrets to some of those principals or allows the use of some secret to be recognized .Distributed Network, such as sensor and mobile ad hoc networks, must conquer a numerous of security challenges to realize their potential in both civil and military applications. Usually, a Distributed Network like ad hoc networks are deployed in untrusted environments. Therefore, authentication is a pioneer to any secure interactions in these networks. Recently, v a r i o u s a u t h e n t i c a t i o n p r o t o c o l s h a ve b e e n proposed for ad hoc networks. In distributed authentication services in ad hoc networks. Two nodes authenticate each other via signed, unforgeable certificates released by a ”virtual“ trusted certification authority. Compared with regular network authentication solutions [28, 29] that rely on physically present, third-party trusted (certification authority) server(s), our design takes a self organized securing approach, in which multiple nodes (say, k) collaboratively serve the role of a certification authority server. Therefore, the authority and functionality of the authentication server are spread to each node’s locality. Any local k nodes are trusted as a whole and collaboratively provide authentication services. This paper describes the authentication procedure and a classification that clarifies similarities and differences among authentication protocol described in the literature. The classification is based upon the role of nodes in the authentication function, establishment of certificate, and type of certificate.

From Implicit to Explicit Transitions in Business Protocols

Modeling Web services is a major step towards their automated analysis. One of the important parameters in this modeling, for the majority of Web services, is the time. A Web service can be presented by its behavior which can be described by a business protocol representing the possible sequences of message exchanges. To the best of the authors’ knowledge, automated analysis of timed Web services (e.g., compatibility and replaceability checking) is very difficult and in some cases it is not possible with the presence of implicit transitions (internal transitions) based on time constraints. The semantics of the implicit transitions is the source of this difficulty because most of well-known modeling tools do not express this semantics (e.g., epsilon transition on the timed automata has a different semantics). This paper presents an approach for converting any protocol containing implicit transitions to an equivalent one without implicit transitions before performing analysis.

TIMED PRIVACY-AWARE BUSINESS PROTOCOLS

Web services privacy issues have been attracting more and more attention in the past years. Since the number of Web services-based business applications is increasing, the demands for privacy enhancing technologies for Web services will also be increasing in the future. In this paper, we investigate an extension of business protocols, i.e. the specification of which message exchange sequences are supported by the web service, in order to accommodate privacy aspects and time-related properties. For this purpose we introduce the notion of Timed Privacy-aware Business Protocols (TPBPs). We also discuss TPBP properties can be checked and we describe their verification process.

A unification-based approach to configure generic protocols into agent interaction models

This paper presents a new approach for generic protocol configuration in agents' internal models. Generic protocols are reusable predefined sequences of message exchanges. Their specifications are most of the time merged with the internal architecture of agents. This requires designers to introduce them by hand every time it is needed. It results in inconsistencies that may occur in message exchange at run time. Inconsistent message exchange in turn results in the failure of the associated interaction. First, we introduce a new language to specify generic protocols. Then we generate the interaction model of agents using their functional model, a generalisation of the design model (only the part devoted to interaction). In order to generate the interaction model, we developed a unification mechanism to automatically check the compliance of a protocol specification with the elements of a functional model. We argue that our approach guarantees that the implementation of the interaction model complies with the initial specification of the protocols it is based on. Here, we discuss the knowledge and reasoning mechanism involved in our approach. An implementation of our approach is also discussed. Particularly, we show the approach's effectiveness with real-world and complex applications.

Deconstructing Alice and Bob

Alice&Bob–notation is a simple notation for describing security protocols as sequences of message exchanges. We show that, despite the fact that Alice&Bob–notation does not include explicit control flow constructs, it is possible to make some of these aspects explicit when producing formal protocol models without having to resort to more expressive protocol description languages. We introduce a notion of incremental symbolic run to formally handle message forwarding and conditional abortion. In incremental symbolic runs, we use variables to represent messages that the principals cannot read, and we characterize each of the execution steps in order to build a collection of symbolic subruns of increasing lengths, reflecting the data possessed by the principals up to that point in the execution. We contrast this with the simpler (more standard) approach based on formalizing the behavior of principals by directly interpreting message exchanges as sequences of atomic actions. In particular, we provide a complete characterization of the situations where this simpler approach is adequate and prove that incremental symbolic runs are more expressive in general.

Formalization, implementation and validation of conversation policies using a protocol operational semantics

Coordination is crucial to the efficiency of multiagent systems. As it is traditionally achieved through message passing, agent communication languages (ACL) have become a major issue in the field. Yet, existing standard technologies, like KQML, are too rigid, and make too strong assumptions when defining their semantics. More importantly, they only allow the specification of individual messages, but hardly permit to deal with sequences of message exchanges—in other words conversations—which is unavoidable if one wants complex and yet efficient interactions to take place. Conversation policies should thus be heavily integrated with ACLs. We present a framework called POS (Protocol Operational Semantics), which is a unification and generalization of existing work on interaction protocols. It does allow the design (syntax and semantics) of dedicated ACLs together with policies or constraints over the use of messages. It is both powerful and particularly easy to implement. It is general enough to allow different types and granularities of constraints. Its similarity with traditional programming languages semantic specifications provides a basis for powerful validation of syntactic and semantic properties, some of which we present in this paper. As an illustration, we give an extended example of the formalization, implementation and validation of a non-trivial protocol, together with its dedicated ACL. Strangely enough, even though conversation policies is a hot topic in multiagent systems (numerous workshops are dedicated to this theme), very few papers deal with protocol validation. This paper makes an inventory of both syntactic and semantic properties conversation policies may satisfy and gives their possible definition. In order to highlight some of those properties we provide an application example and discuss related simulations.

Distributed collection of message exchange sequences in each process for efficient recovery from protocol errors

AbstractIn the fault‐tolerance design of the communication system, one of the important techniques is the protocol error recovery which recovers the normal state from the abnormal state due to the protocol errors generated in the operation of the communication software. The protocol error recovery technique proposed up to now has the following problems: (1) messages are lost in the recovery process; and (2) a long recovery time is required from the error generation to the normal state.This paper proposes a new method to solve those problems and which can realize an accurate and efficient error recovery. More precisely, the condition is derived for avoiding the message loss in the recovery process; and based on the condition, a new protocol error recovery process is formulated. Then another method is proposed in which each process collects the message exchange sequences executed by other processes, together with the ordinary message exchange. A principle of protocol error recovery based on the proposed collection method is shown, indicating that the forementioned problems can be solved.

Protocol analysis and synthesis by structured partitions

Protocols can be viewed as predefined sequences of message exchanges between machines for performing network control functions and for providing network services. One way of modeling protocols is by using communicating finite state machines. The interaction between finite state machines can be very involved, even for machines with few states. To counteract the complexity for protocol analysis and synthesis, we propose a partitioning method based on protocol subgraphs. We found that if there are ‘cross interactions’ involving the entire protocol graph, then the protocol is not decomposable by our technique and must be analyzed or synthesized as a whole. However, if there are subunits of message exchanges within the protocol graph that are self-contained, in other words, if there are no ‘cross interactions’ between protocol subgraphs, then the protocol is decomposable. For protocols that are decomposable, we show that it is only necessary to examine a subspace of the entire reachability space to understand the behavior of the protocol and to guarantee its progress properties. This allows us to analyze and synthesize protocols based on these subgraphs.