A new 2-of-2 Multisignature for Cryptocurrency

In this paper we construct and consider a new group-based 2-of-2 multisignature scheme, which is built using a bilinear map. This map is an asymmetric pairing of Type 3, and although, for the reason of this paper, it is treated in a completely abstract fashion it ought to be viewed as being actually defined over . The idea of the scheme is such that there are two signers with two independent keys  and , that sign the same message. Unlike the regular digital signature schemes, the signing algorithm is split into two phases. Within the first ot them, both signers independently make so-called pre-signatures with their secret keys and send them to the second phase, where the final signatures is derived. The security analysis is conducted within the  model by reducing the security of the scheme to the computational hardness of solving the bilinear Diffie-Hellman inversion problem. The reduction itself is made in the random oracle model.