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The following full text is a preprint version which may differ from the publisher's version. Abstract We describe a largely automated and systematic analysis of TLS implementations by what we call 'protocol state fuzzing': we use state machine learning to infer state machines from protocol implementations, using only black-box testing, and then inspect the(More)
This paper introduces the Smart Logic, which is a flexible smart card research tool that gives complete control over the smart card communication channel for eavesdropping, man-in-the-middle attacks, relaying and card emulation. The hardware is available off-the-shelf at a price of about 100 euros. Furthermore, the necessary firm- and software is open(More)
Learning techniques allow the automatic inference of the behaviour of a system as a finite state machine. We demonstrate that learning techniques can be used to extract such formal models from software on banking smartcards which - as most bank cards do - implement variants of the EMV protocol suite. Such automated reverse-engineering, which only observes(More)
We present a security analysis of an internet banking system used by one of the bigger banks in the Netherlands, in which customers use a USB-connected device – a smartcard reader with a display and numeric keyboard – to authorise transactions with their bank card and PIN code. Such a setup could provide a very strong defence against online attackers,(More)
Mobile phones are increasingly used for security sensitive activities such as online banking or mobile payments. This usually involves some cryptographic operations, and therefore introduces the problem of securely storing the corresponding keys on the phone. In this paper we evaluate the security provided by various options for secure storage of key(More)
State machine learning is a useful technique for automating reverse engineering. In essence, it involves fuzzing different sequences of inputs for a system. We show that this technique can be successfully used to reverse engineer hand-held smartcard readers for Internet banking, by using a Lego robot to operate these devices. In particular , the state(More)
Motivated by Murray's work on the limits of refinement testing for CSP, we propose the use of ProB to check liveness properties under assumptions of strong and weak event fairness, whose refinement-closures cannot generally be expressed as refinement checks for FDR. Such properties are necessary for the analysis of fair exchange protocols in CSP, which(More)
cMix is a suite of cryptographic protocols that can replace today's dominant chat systems, offering superior confidentiality and anonymity, while providing comparable performance to users. cMix permutes batches of uniform-length messages through a fixed cascade of nodes and moves all expensive public-key operations into precomputations that can be carried(More)
Structure-preserving signature schemes can be very useful in the construction of new cryptographic operations like blind signatures. Recently several of these schemes have been proposed. The security of signature-preserving signature schemes is still proved by hand, which can be a laborious task. One of the ways to prove security of these schemes algebraic(More)