Question

Explain knowledge re schemes in brief with suitable example.

Answer 1

To construct a suitable and secure proxy re-signature scheme is not an easy job, up to now, there exist only three schemes, one is proposed by Blaze et al. [6] at EUROCRYPT 1998, and the others are proposed by Ateniese and Hohenberger [2] at ACM CCS 2005. However, none of these schemes is proved in the standard model.