Today's IT-systems store and process an abundance of data.  Some of this data represents private or secret information, and a crucial question is how to ensure that no such information is leaked.

We focus on techniques that establish confidentiality guarantees by controlling the flow of information within IT-systems.  Research on information-flow security has resulted in an impressive portfolio of program analysis techniques and tools.  For sequential programs, these approaches are becoming rather mature, and a good understanding of the resulting, declarative security guarantees has been achieved.  For concurrent programs, information-flow security is more challenging.

The first part of the talk provides an introduction to theory and practice of information-flow control.  The second part clarifies why it is so hard to achieve information-flow security for concurrent programs, and discusses recent results from our on-going research effort to tackle these challenges.