Robert N. M. Watson writes:

Capsicum: practical capabilities for UNIX

Today, Jonathan Anderson, Ben Laurie, Kris Kennaway, and I presented Capsicum: practical capabilities for UNIX at the 19th USENIX Security Symposium in Washington, DC; the slides can be found on the Capsicum web site. We argue that capability design principles fill a gap left by discretionary access control (DAC) and mandatory access control (MAC) in operating systems when supporting security-critical and security-aware applications.

Capsicum responds to the trend of application compartmentalisation (sometimes called privilege separation) by providing strong and well-defined isolation primitives, and by facilitating rights delegation driven by the application (and eventually, user). These facilities prove invaluable, not just for traditional security-critical programs such as tcpdump and OpenSSH, but also complex security-aware applications that map distributed security policies into local primitives, such as Google’s Chromium web browser, which implement the same-origin policy when sandboxing JavaScript execution.

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