conclusions applying a simple and brief scale that incorporates the different dimensions of hiv transmission risk may provide policymakers and harm reductionists with a better understanding of hiv transmission in this key group and may be advantageous for evaluating intervention programs. results we extracted 7 items based on first factor, which were accounted for 21% of the variations. the fin...

Verifiable secret sharing (VSS) schemes [1–3] rely on the assumption that parties can not reliably fabricate false secret shares which pass the verification process. Here, we show that, for certain VSS implementations that use verification commitments bounded to a finite field, this assumption is incorrect. Let there be n shares of a secret and a threshold of t secret shares required to get the...

In many pairing-based cryptosystems, the secret keys are elements of bilinear groups. For safeguarding such secret keys or decrypting or signing in a threshold manner, Verifiable Secret Sharing (VSS) in bilinear groups is required. In this paper, we show a method of verifiably sharing a random secret in a bilinear group. Our method is simple and practical. It can be regarded as a generalisation...

In Shamir’s ( ) t n , threshold of the secret sharing scheme, a secret s is divided into n shares by a dealer and is shared among n shareholders in such a way that (a) the secret can be reconstructed when there are t or more than t shares; and (b) the secret cannot be obtained when there are fewer than t shares. In the secret reconstruction, participating users can be either legitimate sharehol...

Using a data set including album sales, Internet penetration and various demographic measures for 99 American cities over the period 19982003 this paper empirically examines the extent to which file-sharing has caused the US decline in sound recording sales over that period. Also examined is the impact of the Internet on entertainment activities so as to help cleanse the Internet penetration co...

Assume n participants P 1,P 2, . . . , Pn share the knowledge of a multivariable function F and that they want to publicly compute z =F (x1,x2, . . . , xn ), where xi is a secret input provided by Pi . The difficulty is to simultaneously provide the secrecy of each xi and to guarantee the correctness of the common result z . Such a task has been accomplished in [GMW] under the assumption that t...

A proactive secret sharing scheme is a method of sharing a secret among a set of participants. And, the corresponding shadows can be periodically renewed under the premise of never changing the shared secret. However, in the most existing proactive secret sharing schemes, only one secret can be shared during one secret sharing process. The proposed scheme describes PMSS, a new way to share mult...

We continue our discussion of Verifiable Secret Sharing, giving two instantiations of the general schema from the last lecture. First, using Commit(x) = g: Feldman VSS, which leaks nothing but g and is perfect binding. Second, using Perdersen’s commitment Commit(x; r) = gh: Pedersen VSS. Next, we turn to the problem of adaptive security. We describe an adaptively secure Feldman VSS using trapdo...