Użycie czasowych automatów probabilistycznych do modelowania protokołów zabezpieczających

Probabilistic timed automata can be used for modeling and verification of systems whose characteristic is real-time and probabilistic. Analyzing stochastic behavior of network communication, many common points of security protocols and automata can be easily found. Modeling with automata allows to use relations and algorithms, such as bisimulation or minimization. This can lead to verification/simplification protocols.Czasowe automaty probabilistyczne mogą zostać użyte do modelowania i weryfikacji systemów przetwarzanych w czasie rzeczywistym i posiadających cechy probabilistyczne. Biorąc pod uwagę stochastyczne zachowania komunikacji w sieci, można znaleźć wspólne cechy protokołów i automatów. Modelowanie z wykorzystaniem automatów umożliwia użycie relacji i algorytmów, takich jak bisymulacja czy minimalizacja. To może ułatwić weryfikację/uproszczenie protokołów

Towards Most Efficient Method for Untimed Security Protocols Verification

Security protocols are a crucial point of more complicated communication protocols that are responsible for keeping security during data transmission in computer networks. From a security point of view, proper verification of such protocols properties is a significant challenge. In the last decades, many concepts and connected with them verification tools were developed and successfully used for checking protocols correctness conditions. In this area of research, much attention is paid for suitable methods of protocols modelling and a low as possible a computational complexity of algorithms used. The last property is important because it allows practical use of such structures and algorithms for automatic verification. Adding timestamps for protocols schemes caused a need for time modelling in solutions of security protocols verification. Time models added into considerations introduce more complicated structures and increase the complexity of structures and algorithms used in the verification process. According to this, there is still a need of looking for more and more efficient ways for modelling of untimed versions of the protocols, for which adding time will be effective from the verification process point of view. In this paper, we propose a new method for modelling and verification of untimed security protocols properties. We present an idea, examples, an algorithm and experimental results for several protocols. We also compare our results with the best, well-known verification tools

SAT and SMT-Based Verification of Security Protocols Including Time Aspects

For many years various types of devices equipped with sensors have guaranteed proper work in a huge amount of machines and systems. For the proper operation of sensors, devices, and complex systems, we need secure communication. Security protocols (SP) in this case, guarantee the achievement of security goals. However, the design of SP is not an easy process. Sometimes SP cannot realise their security goals because of errors in their constructions and need to be investigated and verified in the case of their correctness. Now SP uses often time primitives due to the necessity of security dependence on the passing of time. In this work, we propose and investigate the SAT-and SMT-based formal verification methods of SP used in communication between devices equipped with sensors. For this, we use a formal model based on networks of communicating timed automata. Using this, we show how the security property of SP dedicated to the sensors world can be verified. In our work, we investigate such timed properties as delays in the network and lifetimes. The delay in the network is the lower time constraint related to sending the message. Lifetime is an upper constraint related to the validity of the timestamps generated for the transmitted messages