5,638 research outputs found
Modelling and simulation of a biometric identity-based cryptography
Government information is a vital asset that must be kept in a trusted environment and efficiently managed by authorised parties. Even though e-Government provides a number of advantages, it also introduces a range of new security risks. Sharing confidential and top-secret information in a secure manner among government sectors tend to be the main element that government agencies look for. Thus, developing an effective methodology is essential and it is a key factor for e-Government success. The proposed e-Government scheme in this paper is a combination of identity-based encryption and biometric technology. This new scheme can effectively improve the security in authentication systems, which provides a reliable identity with a high degree of assurance. In addition, this paper demonstrates the feasibility of using Finite-state machines as a formal method to analyse the proposed protocols
An Experiment in Interoperable Cryptographic Protocol Implementation Using Automatic Code Generation
Spi2Java is a tool that enables semi-automatic generation of cryptographic protocol implementations, starting from verified formal models. This paper shows how the last version of spi2Java has been enhanced in order to enable interoperability of the generated implementations. The new features that have been added to spi2Java are reported here. A case study on the SSH transport layer protocol, along with some experiments and measures on the generated code, is also provided. The case study shows, with facts, that reliable and interoperable implementations of standard security protocols can indeed be obtained by using a code generation tool like spi2Jav
Formally based semi-automatic implementation of an open security protocol
International audienceThis paper presents an experiment in which an implementation of the client side of the SSH Transport Layer Protocol (SSH-TLP) was semi-automatically derived according to a model-driven development paradigm that leverages formal methods in order to obtain high correctness assurance. The approach used in the experiment starts with the formalization of the protocol at an abstract level. This model is then formally proved to fulfill the desired secrecy and authentication properties by using the ProVerif prover. Finally, a sound Java implementation is semi-automatically derived from the verified model using an enhanced version of the Spi2Java framework. The resulting implementation correctly interoperates with third party servers, and its execution time is comparable with that of other manually developed Java SSH-TLP client implementations. This case study demonstrates that the adopted model-driven approach is viable even for a real security protocol, despite the complexity of the models needed in order to achieve an interoperable implementation
Modeling Bitcoin Contracts by Timed Automata
Bitcoin is a peer-to-peer cryptographic currency system. Since its
introduction in 2008, Bitcoin has gained noticeable popularity, mostly due to
its following properties: (1) the transaction fees are very low, and (2) it is
not controlled by any central authority, which in particular means that nobody
can "print" the money to generate inflation. Moreover, the transaction syntax
allows to create the so-called contracts, where a number of
mutually-distrusting parties engage in a protocol to jointly perform some
financial task, and the fairness of this process is guaranteed by the
properties of Bitcoin. Although the Bitcoin contracts have several potential
applications in the digital economy, so far they have not been widely used in
real life. This is partly due to the fact that they are cumbersome to create
and analyze, and hence risky to use.
In this paper we propose to remedy this problem by using the methods
originally developed for the computer-aided analysis for hardware and software
systems, in particular those based on the timed automata. More concretely, we
propose a framework for modeling the Bitcoin contracts using the timed automata
in the UPPAAL model checker. Our method is general and can be used to model
several contracts. As a proof-of-concept we use this framework to model some of
the Bitcoin contracts from our recent previous work. We then automatically
verify their security in UPPAAL, finding (and correcting) some subtle errors
that were difficult to spot by the manual analysis. We hope that our work can
draw the attention of the researchers working on formal modeling to the problem
of the Bitcoin contract verification, and spark off more research on this
topic
Cryptographic Randomized Response Techniques
We develop cryptographically secure techniques to guarantee unconditional
privacy for respondents to polls. Our constructions are efficient and
practical, and are shown not to allow cheating respondents to affect the
``tally'' by more than their own vote -- which will be given the exact same
weight as that of other respondents. We demonstrate solutions to this problem
based on both traditional cryptographic techniques and quantum cryptography.Comment: 21 page
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