The 16th Workshop on Selected Areas in Cryptography (SAC 2009) was held at the University of Calgary,in Calgary, Alberta, Canada, during August 13-14, 2009. There were 74 participants from 19 countries. Previous workshops in this series were held at Queens University in Kingston (1994, 1996, 1998, 1999, and 2005), Carleton University in Ottawa (1995, 1997, and 2003), University of - terloo (2000 and 2004), Fields Institute in Toronto (2001), Memorial University of Newfoundland in St. Johns (2002), Concordia University in Montreal (2006), University of Ottawa (2007), and Mount Allison University in Sackville (2008). The themes for SAC 2009 were: 1. Design and analysis of symmetric key primitives and cryptosystems, incl- ing block and stream ciphers, hash functions, and MAC algorithms 2. E?cient implementations of symmetric and public key algorithms 3. Mathematical and algorithmic aspects of applied cryptology 4. Privacy enhancing cryptographic systems This included the traditional themes (the ?rst three) together with a special theme for 2009 workshop (fourth theme).