@misc{cryptoeprint:2007:421,
    author = {Andr\'e Chailloux and Iordanis Kerenidis},
    title = {The role of help in Classical and Quantum Zero-Knowledge},
    howpublished = {Cryptology ePrint Archive, Report 2007/421},
    year = {2007},
    url = {http://eprint.iacr.org/2007/421},
}