@misc{cryptoeprint:2006:293,
    author = {Zulfikar Ramzan and David P. Woodruff},
    title = {Fast Algorithms for the Free Riders Problem in Broadcast Encryption},
    howpublished = {Cryptology ePrint Archive, Report 2006/293},
    year = {2006},
    url = {http://eprint.iacr.org/2006/293},
}