Directed Threshold Multi &#8211; Signature Scheme without SDC
  In this paper, we propose a Directed threshold multisignature scheme without SDC. This signature scheme is applicable when the message is sensitive to the signature receiver; and the signatures are generated by the cooperation of a number of people from a given group of senders. In this scheme, any malicious set of signers cannot impersonate any other set of signers to forge the signatures. In case of forgery, it is possible to trace the signing set. 
Manoj Kumar