Privacy-preserving multi-party reconciliation using fully homomorphic encryption

Abstract

Fully homomorphic cryptosystems allow the evaluation of arbitrary Boolean circuits on encrypted inputs and therefore have very important applications in the area of secure multi-party computation. Since every computable function can be expressed as a Boolean circuit, it is theoretically clear how to achieve function evaluation on encrypted inputs. However, the transformation to Boolean circuits is not trivial in practice. In this work, we design such a transformation for certain functions, i.e., we propose algorithms and protocols which make use of fully homomorphic encryption in order to achieve privacy-preserving multi-party reconciliation on ordered sets. Assuming a sufficiently efficient encryption scheme, our solution performs much better than existing approaches in terms of communication overhead and number of homomorphic operations. © 2013 Springer-Verlag.