The overall performance of P2P-based file sharing applications is becoming increasingly important. Based on the Adaptive Resource-based Probabilistic Search algorithm (ARPS), which was previously proposed by the authors, a novel probabilistic search algorithm with QoS guarantees is proposed in this letter. The algorithm relies on generating functions to satisfy the user's constraints and to exp...

An (m, n) threshold scheme is to decompose the master key K into n secret shadows in such a way that the master key K cannot be reclaimed unless any m shadows are collected. However, any m 1 or fewer shadows provide absolutely no information about K. In 1989, Laih et al. proposed the concept of dynamic threshold schemes which allow the master key to be updated without changing the secret shadow...

In our proposed scheme, the participants are arranged in a hierarchical structure according to their position or rank and each first level participant as a parent node delegates his power to the lower level hierarchical group members. The group members help to reconstruct the secret shares of their parent nodes in their absence and the secret key is reconstructed even if at least one parent nod...

We present an efficient authenticated and fault-tolerant protocol (AFTD) for tree-based key agreement. Our approach is driven by the insight that when a Diffie-Hellman blinded key is updated, in a tree-based method, it suffices to send the update to a small subset of the group, instead of entire group, as current methods require. Our scheme distributes each updated public key to a relatively sm...

Considering the case of players’ deceptions, traditional secret sharing scheme can not resolve the security issues. To address these security issues, the paper proposes a rational secret sharing scheme against cheating based on game theory. Under the conditions of the rational, applying the idea of threshold, the scheme is composed of key generation, share encryption, verification and secret re...

Recently, some group key transfer protocols are proposed using Shamir’s secret sharing, which are claimed to be secure to resist the insider attack and the outsider attack. In fact, some claims are not really true. In this paper, we review the recently proposed protocol by Yuan et al. and the cryptanalysis presented by Olimid, then give the improved version to guarantee the security and low com...

Running the key-management service of cryptographic systems in the cloud is an attractive cost saving proposition. Supporting key-recovery is an essential component of every key-management service. We observe that to verifiably support key-recovery in a public cloud, it is essential to use publicly verifiable secret-sharing (PVSS) schemes. In addition, a holistic approach to security must be ta...