5th International Workshop on Analysis of Security APIs, 30th June 2011, Submission deadline: April 8th 2011, Paris, France Security APIs allow untrusted code to access sensitive resources in a secure way. Security API analysis is an emerging field of computer security research. The aim of the ASA workshop is to bring together researchers working in security API analysis for a day of presentations and discussions. Since the field is relatively young, polished research papers will not be solicited. Instead, the workshop will follow the format that was highly successful at ASA in 2007-10: prospective participants are invited to submit a short (1-4 page) abstract describing their current work and/or interests in the area. We plan to have two sessions of 20-minute talks by participants, with each session followed by informal discussion. There will also be a workshop dinner in the evening, and subject to confirmation, an invited speaker. The scope of ASA runs from theoretical results and formalisms for API analysis right through to applications and empirical results with security APIs deployed `in the field'. Applications of interest include (but are not limited to) financial applications (e.g. APIs of Hardware Security Modules), smartcard APIs, the Trusted Computing Architecture, and security APIs for web based systems. http://www.lsv.ens-cachan.fr/~steel/asa5/