Practical hierarchical identity based signature in the standard model

Hierarchical ID-based signature (HIBS) scheme is a generalization of identity based signature. It allows a root PKG to generate private keys for domain-level PKGs, who in turn generate private keys for their users in the domains of the lower level. A practical hierarchical identity based signature scheme (HIBS) based on bilinear parings is proposed. Assuming the intractability of the computational Diffie-Hellman problem, our HIBS is unforgeable under adaptive chosen-message and ID attack in the standard model. The number of public parameters is significantly less compared to the scheme that is constructed by using Waterspsila method. We also have presented a variety of techniques to improve its space requirements and computational requirements and briefly analyzed the aggregation properties of our scheme.