Trusted Authority for Identifier-Based Cryptography

摘要

A trusted authority (70) is provided for identifier-based cryptography using bilinear maps. The trusted authority has a secret (r) and derives first and second elements (QTA2,Y) at least the second of which it publishes. The first element (QTA2) is derived from an identifier ("TA2") associated with the trusted authority; the second element (Y) is a combination of the first element (QTA2) and the secret (r). The trusted authority (70) provides a private-key generation service involving the generation of a private key (rQBob) for a third party (80) in dependence on the secret (r) and an identifier string ("Bob") associated with that third party.