In a threshold signature scheme, a group of players shares some secret information in such a way that only those subsets with a minimum number of players can compute a valid signature. In this paper we propose methods to construct some computationally secure distributed protocols from threshold signature schemes. Namely, we construct metering schemes from threshold non-interactive signature sch...

background: the effect of psychosocial work environment on personal and organizational aspects of employees is well-known and it is of fundamental importance to have valid tools to evaluate them. this study aims to evaluate the reliability and validity of the persian version of copenhagen psychosocial questionnaire (copsoq).   methods : the questionnaire was translated into persian and then bac...

Sun’s nonrepudiation threshold proxy signature scheme is not secure against the collusion attack. In order to guard against the attack, Hwang et al. proposed another threshold proxy signature scheme. However, a new attack is proposed to work on both Hwang et al.’s and Sun’s schemes. By executing this attack, one proxy signer and the original signer can forge any valid proxy signature. Therefore...