Progress On Certifying Algorithms

A certifying algorithm is an algorithm that produces with each output, a certificate or witness (easy-to-verify proof) that the particular output has not been compromised by a bug. A user of a certifying program P (= the implementation of a certifying algorithm) inputs x, receives an output y and a certificate w, and then checks, either manually or by use of a checking program, that w proves that y is a correct output for input x. In this way, he/she can be sure of the correctness of the output without having; to trust P. We refer the reader to the recent survey paper [9] for a detailed discussion of certifying algorithms.