Rossana Motta

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We investigate an application of RFIDs referred to in the literature as group scanning, in which several tags are “simultaneously” scanned by a reader device. Our goal is to study the group scanning problem in strong adversarial models. We present a security model for this application and give a formal description of the attending security requirements,(More)
A considerable number of anonymous RFID authentication schemes have been proposed. However, current proposals either do not provide robust security guarantees, or suffer from scalability issues when the number of tags issued by the system is very large. In this paper, we focus on approaches that reconcile these important requirements. In particular, we seek(More)
In the absence of sufficiently optimised public key constructions, anonymous authentication for Radio-Frequency Identification Devices (RFIDs) requires state synchronisation between tags and a trusted server. Active adversaries disrupt this synchrony, making a recovery strategy necessary. In some protocols, tags recover by replaying previously used values,(More)
P2P is currently considered a problem by many wired and wireless providers, especially because of the large amount of traffic it generates. However, given new technology developments such as Wi-Fi Direct, we see an opportunity for P2P in mobile settings that, rather than treating mobiles as second-class citizens, seeks to take advantage of their(More)
Peer-To-Peer (P2P) systems have made an enormous impact on the Internet, directly affecting its performance and security. The litigation against P2P file sharing has led some designers to opt for purely decentralized P2P models. The latter have quickly become attractive to Internet users, who often consider pure P2P as more "secure" than hybrid systems(More)
Replicated storage systems allow their stored data objects to outlive the life of the nodes storing them through replication. In this paper, we focus on durability, and more specifically on the concept of an object's lifetime, i.e., the duration of time between the creation of an object and when it is permanently irretrievable from the system. We analyze(More)
Replicated storage systems allow their stored data to outlive the life of the nodes storing them by use of replication. In such systems, failed replicas are “repaired” by copying remaining replicas from other nodes. We consider two main replication strategies: reactive, in which replication occurs in response to failures, and proactive, in(More)
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