We present hierarchical identity-based encryption schemes and signature schemes that have total collusion resistance on an
arbitrary number of levels and that have chosen ciphertext security in the random oracle model assuming the difficulty of
the Bilinear Diffie-Hellman problem.
Keywords identity-based cryptography - hierarchical identity-based cryptography - elliptic curves - pairing-based cryptography
Silverberg would like to thank DoCoMo USA Labs for support and kind hospitality during her visit there.