96,446 research outputs found
Novel Contract Signature based on Key Exchange
A contract signature is a particular form of digital multi-signature that only involves two signers. Contract signing plays a critical role in any business transaction, particularly in situations where the involved parties do not trust each other. One of the most significant concerns in exchange signatures is the fraudulent and unfair exchange, which occurs when one party gets the signature of another party without giving his own signature. In the view of these security concerns, this thesis presents a secure and fair contract signature scheme based on key exchange protocol. The security and protection of the proposed scheme is based on solving hard computational assumptions such as discrete logarithm problem (DLP). The proposed protocol is abuse-free. The proposed scheme targets to have lesser computational overhead and high-security features than existing scheme[1]. The proposed scheme has wide application in real life scenarios, such as in electronic cash system
TumbleBit: an untrusted Bitcoin-compatible anonymous payment hub
This paper presents TumbleBit, a new unidirectional unlinkable payment hub that is fully compatible with today s Bitcoin protocol. TumbleBit allows parties to make fast, anonymous, off-blockchain payments through an untrusted intermediary called the Tumbler. TumbleBits anonymity properties are similar to classic Chaumian eCash: no one, not even the Tumbler, can link a payment from its payer to its payee. Every payment made via TumbleBit is backed by bitcoins, and comes with a guarantee that Tumbler can neither violate anonymity, nor steal bitcoins, nor print money by issuing payments to itself. We prove the security of TumbleBit using the real/ideal world paradigm and the random oracle model. Security follows from the standard RSA assumption and ECDSA unforgeability. We implement TumbleBit, mix payments from 800 users and show that TumbleBits offblockchain payments can complete in seconds.https://eprint.iacr.org/2016/575.pdfPublished versio
Inductive benchmarking for purely functional data structures
Every designer of a new data structure wants to know how well it performs in comparison with others. But finding, coding and testing applications as benchmarks can be tedious and time-consuming. Besides, how a benchmark uses a data structure may considerably affect its apparent efficiency, so the choice of applications may bias the results. We address these problems by developing a tool for inductive benchmarking. This tool, Auburn, can generate benchmarks across a wide distribution of uses. We precisely define 'the use of a data structure', upon which we build the core algorithms of Auburn: how to generate a benchmark from a description of use, and how to extract a description of use from an application. We then apply inductive classification techniques to obtain decision trees for the choice between competing data structures. We test Auburn by benchmarking several implementations of three common data structures: queues, random-access lists and heaps. These and other results show Auburn to be a useful and accurate tool, but they also reveal some limitations of the approach
An Epistemic Approach to Coercion-Resistance for Electronic Voting Protocols
Coercion resistance is an important and one of the most intricate security
requirements of electronic voting protocols. Several definitions of coercion
resistance have been proposed in the literature, including definitions based on
symbolic models. However, existing definitions in such models are rather
restricted in their scope and quite complex.
In this paper, we therefore propose a new definition of coercion resistance
in a symbolic setting, based on an epistemic approach. Our definition is
relatively simple and intuitive. It allows for a fine-grained formulation of
coercion resistance and can be stated independently of a specific, symbolic
protocol and adversary model. As a proof of concept, we apply our definition to
three voting protocols. In particular, we carry out the first rigorous analysis
of the recently proposed Civitas system. We precisely identify those conditions
under which this system guarantees coercion resistance or fails to be coercion
resistant. We also analyze protocols proposed by Lee et al. and Okamoto.Comment: An extended version of a paper from IEEE Symposium on Security and
Privacy (S&P) 200
- …