How to Obtain and Assert Composable Security

Capturing the security requirements of distributed systems and applications in a meaningful way is a subtle and tricky business. Assessing whether given protocols meet these requirements is even trickier. One major stumbling point is protocol composition, namely the often unexpected vulnerabilities that result from the interference between protocols in a multi-protocol system. Indeed, security analysis of protocols has traditionally been very fragile with respect to protocol composition. It was even suggested that composable security may be impossible to achieve in general.

The framework of Universally Composable security, proposed in 2001, allows one to design and analyze protocols in a way that guarantees security even when the protocol runs in an arbitrary multi-protocol system. In particular, it allows one to assert the security of protocols in unpredictable, complex environments such as the global Internet. It also enables the security analysis of complex systems to be modular, hence drastically simpler.

This talk motivates and presents the paradigm of Universally Composable security. It then briefly reviews some of the recent research done within this paradigm and on it. Part of this research touches foundational aspects in security and cryptography. Other parts have immediate practical implications.

Ran Canetti graduated from the Weizmann Institute of Science in 1995. He is currently a researcher at the Cryptography group, IBM T.J. Watson Research Center, and a visiting scientist at the Cryptography and Information Security group, CSAIL, MIT. Ran's research interests lie in cryptography and network security, with emphasis on the design and analysis of cryptographic protocols. Ran has also contributed to the security work done at the IETF, including co-designing the HMAC protocol, contributing to the design of the IPSec, TLS, and MSec protocols, and co-chairing the Multicast Security working group and the Crypto Forum research group. See also http://people.csail.mit.edu/canetti.