Daniel W. Engels Xinxin Fan Guang Gong Honggang Hu Eric M. Smith Hummingbird: Ultra-Lightweight Cryptography for Resource-Constrained Devices. 3-18 2010 Financial Cryptography Workshops http://dx.doi.org/10.1007/978-3-642-14992-4_2 conf/fc/2010w db/conf/fc/fc2010w.html#EngelsFGHS10