Binary Tree Encryption: Constructions and Applications

Binary tree encryption (BTE), a relaxation of hierarchical identity-based encryption (HIBE), has recently emerged as a useful and intriguing primitive. On the one hand, the definition of security for BTE is sufficiently “weak” that — in contrast to HIBE — constructions of BTE in the standard model are known. On the other hand, BTE is sufficiently powerful that it yields a number of applications which are important from both a theoretical and a practical point of view. This survey presents the basic definitions of BTE and also highlights some recent applications of BTE to forward-secure encryption, identitybased and hierarchical identity-based encryption, chosen-ciphertext security, and adaptively-secure encryption.