@misc{cryptoeprint:2015:131,
    author = {Frederik Armknecht, Vasily Mikhalev},
    title = {On Lightweight Stream Ciphers with Shorter Internal States},
    howpublished = {Cryptology ePrint Archive, Report 2015/131},
    year = {2015},
    url = {https://eprint.iacr.org/2015/131},
}