@misc{cryptoeprint:2012:248,
    author = {Ghassan O. Karame and Elli Androulaki and Srdjan Capkun},
    title = {Two Bitcoins at the Price of One? Double-Spending Attacks on Fast Payments in Bitcoin},
    howpublished = {Cryptology ePrint Archive, Report 2012/248},
    year = {2012},
    url = {http://eprint.iacr.org/2012/248},
}