@misc{cryptoeprint:2007:183,
    author = {Ling Cheung and Calvin Newport},
    title = {Provably Secure Ciphertext Policy ABE},
    howpublished = {Cryptology ePrint Archive, Report 2007/183},
    year = {2007},
    url = {http://eprint.iacr.org/2007/183},
}