A self-certified group-oriented cryptosystem without a combiner

Abstract

In a (t; n) group-oriented cryptosystem, collaboration of at least t participants is required to perform the group transformation. Two important issues in implementation of a such cryptosystems are:

1. the sender needs to collect authenticated public keys of the intended receivers;

2. the combiner needs a secure channel to collect (privately) the partial results from collaborating participants.

This paper discusses the above problems and proposes a (t; n) group-oriented cryptosystem that works with self-certified public keys, with no help of any combiner.