Alice, a peer in a peer-to-peer (P2P) network can evaluate the reputation of another peer, Bob, either based on her own experiences (with Bob) or based on the evaluation (of Bob) by others (say Carol and David). If Alice uses her own experiences only, she will get cheated atleast once for every malicious peer she identifies. If Alice uses third party experiences (Carol and David), she can reduc...

In physical layer security (PHY-security), the frequently observed high correlation between the main and wiretap channels can cause a significant loss of secrecy. This paper investigates a slow fading scenario, where a transmitter (Alice) sends a confidential message to a legitimate receiver (Bob) while a passive eavesdropper (Eve) attempts to decode the message from its received signal. It is ...

Proxy re-encryption is a cryptographic primitive proposed by Blaze, Bleumer and Strauss in 1998. It allows a user, Alice, to decide that in case of unavailability, one (or several) particular user, the delegatee, Bob, will be able to read her confidential messages. This is made possible thanks to a semi-trusted third party, the proxy, which is given by Alice a re-encryption key, computed with A...

" If you don't know where you are going, any road will take you there. " It is one of my favorite sayings. It always reminds me that if you and I don't have a plan of some kind, then we will wander aimlessly toward whatever. And generally, if we have not thought out where we are going, or where we would like to go, then other people, or life circumstances, will create the way for us. I heard th...

Delivering quantum-encoded secret keys is known as Quantum Key Distribution, or QKD; in essence it involves transmitting a series of randomly generated, quantum-encoded bits of information between a sender and a receiver, Alice and Bob, over a distance. This string of bits, called qubits, becomes the secret key Alice and Bob use to interpret encoded messages sent over less-secure channels. In t...

Suppose Alice is a on a trip to a computer security conference. Her coworker, Bob, stays behind to watch over their cubicles. Suddenly, Alice remembers that she forgot to send an important memo to Bob. No problem, she thinks – there are computers available at the conference, and she can just fire off an email to Bob. Because it’s so important, Alice is going to want to sign the memo. Because Al...

We introduce mCP nets, an extension of the CP net formalism to model and handle the qualitative and conditional preferences of multiple agents. We give a number of different semantics for reasoning with mCP nets. The semantics are all based on the idea of individual agents voting. We describe how to test optimality and preference ordering within a mCP net, and we give complexity results for suc...

In this paper we investigate a variation of the graph coloring game, as studied in [2]. In the original coloring game, two players, Alice and Bob, alternate coloring vertices on a graph with legal colors from a fixed color set, where a color α is legal for a vertex if said vertex has no neighbors colored α. Other variations of the game change this definition of a legal color. For a fixed color ...

Joanne Brown Program Leader, Alcohol Tobacco and othe Drugs Service, Queensland Health, Cairns. Ernest Hunter Regional Psychiatrist, Queensland Health, Cairns. Kate Conigrave Associate Professor, The University of Sydney. Peter d’Abbs Associate Professor, James Cook University, Cairns. John Boffa Public Health Medical Officer, Central Australian Aboriginal Congress, Alice Springs. Craig Gallagh...