Citation Context

... of coercion resistance and receipt freeness. Our formalisation highlights the variation between the definitions, and the importance of understanding the relations between them. 1 Introduction Much work has been published over the last couple of decades concerning secure voting protocols. Many proposals come with claims that they meet appropriate security guarantees; but the properties in question are often poorly defined, and for the most part any proofs offered have been informal at best. More recently, there have been attempts to formalize some of the desirable properties of voting systems [MN06,DKR09,DLL11]. These results have been useful, because they have been able to give precise answers to previously vague questions about the security of various systems. The approach has been to construct a model, and to verify it against a formalization of the relevant property. However, since the informal definitions vary considerably, these formal definitions inevitably capture what is meant by some authors’ use of the terms, and not others’; consequently, one can debate whether the formalisms really have captured the ‘right’ understanding of the various properties. Our approach here is a little different...

Citation Context

...an existing system, areas for privacy improvement can be identified. We have developed tools to automatically obtain a coalition graph from a formal model of communication. Other formal methods, e.g. =-=[1, 2, 4, 5, 7, 19]-=-, analyse knowledge of communicating actors. These methods verify that particular information cannot be derived by particular actors. In contrast, we express all relevant knowledge of all coalitions o...

Citation Context

...ing attention and it is frequently used to express security properties of cryptographic protocols. Examples include stronger notions of secrecy and privacy-related . properties of voting and auctions =-=[12, 14, 15, 16]-=-, gamebased notions such as ciphertext indistinguishability [5], and authenticated key-exchange security [6, 18]. Our focus in this paper is on symbolic models [4] for observational equivalence. The k...

Citation Context

...44] introduced a simulation based definition for coercion resistance. Backes et al. [6] introduced a definition of coercion resistance in symbolic model which was more suitable for automation than previous works. Meng [39] provided a state of the art survey on the definitions of receipt-freeness and coercion-resistance and on what technologies are used at the time to implement these property in voting schemes. Kuesters et al. [34] introduced a formalisation of coercion resistance which could provide a probabilistic measure of the amount of coercion resistance in a voting scheme. Dreier et al. [22] provided formal definitions of various privacy notions in applied pi calculus, and showed how they are related to each other. Several works such as [38, 36, 1, 35, 32, 51, 5, 48], without introducing new definitions of receipt freeness and coercion resistance properties, have developed weaker, more practical, or more efficient ways to realize the needed assumptions for achieving these properties (assumptions such as existence of untappable channels, anonymous channels, etc.). Also some works, such as [28, 7, 33] have used formal logic to express coercion resistance property in elections. Junk...

Citation Context

...e a direct participant in the communication under analysis). Recently, several research efforts have focused on the analysis of privacy properties using the applied pi calculus and related techniques =-=[21, 42, 43, 45, 91]-=-, in application domains such as electronic toll collection [42], e-voting [43, 45], and RFID systems [21]. While this approach has delivered considerable successes, several issues inhibit its use for...