The security devroom topic this year is
Security and Privacy in
Cryptography has been the foundation of modern crypto software, however, it is only a small fraction of the technology required to achieve security and privacy for users. Thus this year's topic is to focus on the other parts that make software secure: usability, the protection against side-channels, message length analysis, fingerprinting, secure coding practices, code review processes etc. We welcome presentations of security software and hardware which take into account these factors, and presentations that analyze other's solutions.
See https://github.com/security-devroom/fosdem-2017 for more information.