@misc{cryptoeprint:2017:158,
    author = {Martin Potthast and Christian Forler and Eik List and Stefan Lucks},
    title = {Passphone: Outsourcing Phone-based Web Authentication while Protecting User Privacy},
    howpublished = {Cryptology ePrint Archive, Report 2017/158},
    year = {2017},
    url = {https://eprint.iacr.org/2017/158},
}