Beijing Jiaotong University
In this paper, the authors propose a new efficient Hierarchical Identity Based Signature (HIBS) scheme. Their scheme can be proven probably secure based on a natural hardness assumption (i.e. h-exponent Computational Diffie-Hellman problem (h-CDH)) in the standard model. Their scheme only requires three pairing computations in verification, which has no relations with the hierarchy. Their scheme has constant signature size, and the length of a user's private key is shrinking as the depth increases. Most importantly, their scheme is non-public-verifiable.