Structural Identity-Based Encryption.
Man Ho Au, Siu‐Ming Yiu · IACR Cryptology ePrint Archive · 2007
In this paper, we introduce the concept of structural identitybased encryption (SIBE). Similar to hierarchical identity-based encryption (HIBE), entities in the system are organized into hierarchy. An entity in SIBE can decrypt ciphertext for all its ancestors. It can be seen as an opposite of HIBE, where an entity can decrypt the ciphertext for all its descendants. We formalize the notion and security requirements, propose an efficient construction and show that our construction is secure under appropriate assumptions in the random oracle model.