Multi-proxy signatures based on Diffie-Hellman problems allowing repeated delegations

Abstract

Because the Internet is vast and insecure, strong cryptographic protocols are required to support secure communication. In this paper, we propose an efficient way to perform secure delegations in a hierarchical group. We propose a practical multi-proxy signature scheme applicable to hierarchial organization using the Diffie-Hellman problem and secret sharing without secure channels. In addition, we improve the proposed scheme to a dynamic one allowing repeated delegations. © Springer-Verlag Berlin Heidelberg 2005.