of cryptographic communicating parties to share a key which is known to no systems, which minimize the need for secure key distribution one else. This is done by sending the key in advance over some channels and supply the equivalent of a written signature. This secure channel such a private courier or registered

(AWGN) channels, which may be good models for hybrid transmission applications such as digital audio broadcasting, and mean-square-error-constrained attack channels that model private-key watermarking applications.

This paper presents a modified version (DHBT-E) of an existing two-party key agreement protocol (DH-BT) used for efficiently establishing secure communication sessions in local wireless networks. A formal security analysis in the model of Bellare and Rogaway is provided to justify the relevant security properties and thus to enforce trustworthiness. The basic intuition is that key agreement in open-air-networks should provide forward secrecy, since eavesdropping is essentially for free and hence may give the adversary a small but significant advantage. For this reason, the protocol uses basic Diffie-Hellmann key exchange. Entity authentication is based on the shared string model, with the key formed by two cryptographic component keys (one key being eventually a low-entropy human memorable string), thus guaranteeing a stronger (two-factor) level of security. Key words: Wireless networks, Diffie-Hellman key exchange, Symmetric key

. In particular, the “complaint phase”, in which cheaters are thrown out, makes the scheme overly complex and difficult to deal with in practical situations. In order to avoid this phase and other drawbacks such as the initialization phase where private channels have to be created, we present a one round scheme

setup phase. The scheme also utilizes private channels between each pair of parties. The Sender is able to easily commit to a large value; the scheme is not just a "bit-commitment " scheme. We also observe that 1-out-of-n oblivious transfer is easily handled in the same model, using a

We investigate how a classical private key can be used by two players, connected by an insecure one-way quantum channel, to perform private communication of quantum information. In particular we show that in order to transmit n qubits privately, 2n bits of shared private key are necessary

Abstract. Can you guarantee secrecy even if an adversary can eavesdrop on your brain? We consider the problem of protecting privacy in circuits, when faced with an adversary that can access a bounded number of wires in the circuit. This question is motivated by side channel attacks, which allow

One aspect of security in mobile code is privacy: private (or secret) data should not be leaked to unauthorised agents. Most of the work on secure information flow has until recently only been concerned with detecting direct and indirect flows. Secret information can however be leaked

Abstract not found

Abstract Suppose that some parties are connected by an incomplete network of reliable and private channels.The parties cooperate to execute some protocol. However, the parties are curious- after the protocol