It is our pleasure to welcome you to the third edition of the International Symposium on Engineering Secure Software and Systems. This unique event aims at bringing together researchers from software engineering and security engineering, which might help to unite and further develop the two communities in this and future editions. The parallel technical sponsorships from the ACM SIGSAC (the ACM interest group in security) and ACM SIGSOF (the ACM interest group in software engineering) is a clear sign of the importance of this interdisciplinary research area and its potential. The difficulty of building secure software systems is no longer focused on mastering security technology such as cryptography or access control models. Other important factors include the complexity of modern networked software systems, the unpredictability of practical development life-cycles, the intertwining of and trade-off between functionality, security and other qualities, the difficulty of dealing with human factors, and so forth. Over the last few years, an entire research domain has been building up around these problems.