The need for communication privacy over public networks is of growing
concern in today's society. As a result, privacy-preserving authentication
and key exchange protocols have become critical primitives in building
secure distributed systems. Secret handshakes provide such a service by
allowing two members of the same group to secretly and privately
authenticate to each other and agree on a shared key for further
In previous work, secret handshakes were extended with roles, so that a
group member A can specify the role another group member B must have in
order to successfully complete the protocol with A. Such extensions is what
makes secret handshakes an interesting problem to work on. In this talk I
will present the first efficient secret handshake schemes where user
credentials are reusable and unlinkable at the same time. In addition, we
significantly extend the flexibility of secret handshakes by allowing each
party to specify both the group and the role the other must have in order to
complete the handshake. Furthermore, we let secret handshakes to be
attribute-based, allowing for approximate (or fuzzy) matching.
We demonstrate the practicality and efficiency of our protocols (which are
built from an identity-based encryption scheme) by evaluating a prototype
implementation and integrating our dynamic matching protocol into IPsec.
Our experiments indicate that our solutions offer attractive performance.
Marina Blanton is a Ph.D. student in the Department of Computer Science at
Purdue University in her final year. She received MS in CS from Purdue
University in 2004 and MS in EECS from Ohio University in 2002. Marina's
research interests lie in information security and, in particular, she has
done work on anonymity in access control systems, key management and
authentication, privacy-preserving computation, and applied cryptography.
More information can be found at http://www.cs.purdue.edu/homes/mbykova.