In a classic paper, among a multitude of other security issues, Claude E. Shannon defined perfect secrecy for a pair of secure computers communicating over an insecure link. The present paper extends Shannon’s notion of perfect secrecy to ad hoc wireless networks of computers. All of the wireless transmissions are insecure. This paper assumes a secure base-station communicating wirelessly using...

In the spirit of Shannon's theory of secrecy systems we analyse several possible natural deenitons of the notion of perfect secrecy; these deenitions are based on arguments taken from probability theory, information theory, the theory of computational complexity, and the theory of program-size complexity or algorithmic information. It turns out that none of these deenitions models the intuitive...

In the spirit of Shannon's theory of secrecy systems we analyse several possible natural de nitons of the notion of perfect secrecy; these de nitions are based on arguments taken from probability theory, information theory, the theory of computational complexity, and the theory of program-size complexity or algorithmic information. It turns out that none of these de nitions models the intuitive...

There are two key properties of the above. First, given only c, Eve should not be able to learn what m is. Second, Dec(Enc(m)) = m, so that Bob can accurately determine the message that Alice wanted to send. Creating functions Enc and Dec which satisfy this is a fundamental problem of cryptography. But given the above encryption scheme, knowing what these functions are is enough for anyone to d...

We study the secrecy capacity in the vicinity of colluding eavesdroppers. Contrary to the perfect collusion assumption in previous works, our new information-theoretic model considers constraints in collusion. We derive the achievable secure rates (lower bounds on the perfect secrecy capacity), both for the discrete memoryless and Gaussian channels. We also compare the proposed rates to the non...

Most voting schemes rely on a number of authorities. If too many of these authorities are dishonest then voter privacy may be violated. To give stronger guarantees of voter privacy Kiayias and Yung [1] introduced the concept of elections with perfect ballot secrecy. In this type of election scheme it is guaranteed that the only thing revealed about voters’ choices is the result of the election,...

In contrast to the pessimistic view on perfect secrecy, studies on information-theoretic secrecy have shown that perfect secrecy may be possible in practice. A typical example is the Wyner’s wire-tap channel concept. However, existing approaches mostly depend on unrealistic noise or error-rate assumptions. We propose a more practical way in this paper which uses advanced space-time transmission...