1. Narayanan M, Shmatikov V (2005) Fast dictionary attacks on passwords using timespace tradeoff. In: Proceedings of the 12th ACM conference on computer and communications security, pp 364–372
2. John the Ripper password cracker. Openwall Project. http://www.openwall.com/john
3. Ur B, Noma F, Bees J, Segreti SM, Shay R, Bauer L, Christin N, Cranor LF (2015) I added’!’at the end to make it secure: Observing password creation in the lab. In: Eleventh symposium on usable privacy and security (SOUPS 2015), pp 123–140
4. Karapanos N, Marforio C, Soriente C, Capkun S (2015) Sound-proof: usable two-factor authentication based on ambient sound. In: 24th USENIX security symposium (USENIX security 15), pp 483–498
5. Wang D, Wang P (2016) Two birds with one stone: two-factor authentication with security beyond conventional bound. IEEE Trans Depend Secure Comput 15(4):708–722