 Such a proof must imply that the consumer can trust the compiler used by the supplier and that the certificate, the information about the source code, can be verified.The figure illustrates how certification and verification of low-level code could be established by the use of a certifying compiler.The software supplier gains the advantage of not having to reveal the source code, and the consumer is left with the task of verifying the certificate, which is an easy task compared to evaluation and compilation of the source code itself.