Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded

We propose a reputation-based trust management system, ROCQ, to reduce inauthentic and corrupted file transfers in end-user collaborative content-distribution systems. Such systems are characterized by the splitting of large files into (optionally encoded) blocks and the simultaneous downloading

Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded

In this work we study the effectiveness of mechanisms for decentralized reputation management in P2P networks. We depart from EigenTrust [7], an algorithm designed for reputation management in file sharing applications over p2p networks. EigenTrust has been proved very effective against three

In this work we study the effectiveness of mechanisms for decentralized reputation management in P2P networks. We depart from EigenTrust, an algorithm designed for reputation management in file sharing applications over p2p networks. EigenTrust has been proved very effective against three different

Establishing secure communication among a group of physically collocated people is a challenge. This problem can be reduced to establishing authentic public keys among all the participants – these public keys then serve to establish a shared secret symmetric key for encryption and authentication of messages. Unfortunately, in most real-world settings, public key infrastructures (PKI) are uncommon and distributing a secret in a public space is difficult. Thus, it is a challenge to exchange authentic public keys in a scalable, secure, and easy to use fashion. In this paper, we propose GAnGS, a protocol for the secure exchange of authenticated information among a group of people. In contrast to prior work, GAnGS resists Groupin-the-Middle and Sybil attacks by malicious insiders, as well as infiltration attacks by malicious bystanders. GAnGS is designed to be robust to user errors, such as miscounting the number of participants or incorrectly comparing checksums. We have implemented and evaluated GAnGS on Nokia N70 phones. The GAnGS system is viable and achieves a good balance between scalability, security, and ease of use.