Single Private-Key Generator Security Implies Multiple Private-Key Generators Security

This paper discusses the security of identity-based cryptography with multiple private-key generators (mPKG-IBC). Most mPKG-IBC schemes and protocols are statically secure where private-key generators (PKGs) cannot control a binding between a party and its PKG. We propose adaptive security notions for identity-based key encapsulation mechanism with multiple private-key generators, identity-based signature with multiple private-key generators, and identity-based authenticated key exchange with multiple private-key generators, respectively. In additions, we provide their generic constructions of those from identity-based key encapsulation mechanism, identity-based signature, and identity-based authenticated key exchange which are secure in a single PKG model, respectively.