Abstract:

The problem in which one of three pairwise interacting parties is required to securely compute a function of the inputs held by the other two, when one party may arbitrarily deviate from the computation protocol (active behavioral model), is studied. An information-theoretic characterization of unconditionally secure computation protocols under the active behavioral model is provided. A protocol for Hamming distance computation is provided and shown to be unconditionally secure under both active and passive behavioral models using the information theoretic characterization. The difference between the notions of security under the active and passive behavioral models is illustrated by examining a protocol for computing quadratic and Hamming distances that is secure under the passive model, but is insecure under the active model.