We address the problem of allowing authorized users, who have yet to establish a secret key, to securely and efficiently exchange key establishment messages over an insecure channel in the presence of jamming and message insertion attacks. This problem was first introduced by Strasser, Pöpper, Čapkun, and Čagalj in their recent work, leaving joint consideration of security and efficiency as an open problem. In this paper, we present three approaches based on coding theory which reduce the overall time required to verify the packets and reconstruct the original message in the presence of jamming and malicious insertion. We first present the Hashcluster scheme which reduces the total overhead included in the short packets. We next present the Merkleleaf scheme which uses erasure coding to reduce the average number of packet receptions required to reconstruct the message. We then present the Witnesscode scheme which uses one-way accumulators to individually verify packets and reduce redundancy. We demonstrate through analysis and simulation that our candidate protocols can significantly decrease the amount of time required for key establishment in comparison to existing approaches without degrading the guaranteed level of security.

In developing secure applications and systems, designers must often incorporate secure user identification in the design specification. In this paper, we study secure off-line authenticated user identification schemes based on a biometric system that can measure a user's biometrics accurately (up to some Hamming distance). The presented schemes enhance identification and authorization in secure applications by binding a biometric template with authorization information on a token such as a magnetic strip. Also developed are schemes specifically designed to minimize the compromising of a user's private biometrics data, encapsulated in the authorization information, without requiring secure hardware tokens. We also study the feasibility of biometrics performing as an enabling technology for secure systems and applications design. We investigate a new technology which allows a user's biometrics to facilitate cryptographic mechanisms.

The author describes the use of cryptographic authentication for controlling computer viruses. The objective is to protect against viruses infecting software distributions, updates, and programs stored or executed on a system. The authentication determines the source and integrity of an executable, relying on the source to produce virus-free software. The scheme relies on a trusted (and verifiable, where possible) device, the authenticator, used to authenticate and update programs and convert programs between the various formats. In addition, each user's machine uses a similar device to perform run-time checking.>