An information-theoretic approach for secure protocol composition

Abstract

Privacy protection has become a crucial issue in the information era. In recent years, many protocols have been developed to accomplish computational tasks collaboratively without revealing the participants’ private data. However, developing protocols for each individual application would not be practical. The more natural and efficient approach would be utilizing basic protocols as building blocks for the construction of complex protocol. In this paper, we proposed the concept of t-certified protocols, which are protocols that are secure when t parties are under the influence of a semi-honest adversary. A composition theorem is given to specify the conditions for secure composition of t-certified protocols, and a framework for constructing complex protocols is developed. We have adopted an information theoretical approach, and believe that it will be a viable alternative to the classic simulator approach, which is based on the concept of indistinguishability between the ideal model and the real model.