@InProceedings{Kelley:USEC13, 
        author = "P. Kelley and S. Komanduri and M. Mazurek and R. Shay and T. Vidas and L. Bauer and N. Christin and L. Cranor",
        title = "The impact of length and mathematical operators on the usability and security of system-assigned one-time {PIN}s",
        booktitle = "Proceedings of the 2013 Workshop on Usable Security (USEC'13)",
        month = "April",
        year = 2013, 
        address = "Okinawa, Japan"
}