Software Based Fault Tolerance against Byzantine Failures

The proposed software technique is a very low cost and an effective solution towards designing Byzantine fault tolerant computing application systems that are not so safety critical. It does not rely on multiple versions of software running simultaneously on multiple machines. The proposed software approach is to mask various hardware random errors on adopting the so-called, ESVP (an enhanced single -version program) scheme, while an application is being executed. It is not intended to eliminate software design bugs. In other words, it is assumed that code is correct and the faulty behavior is only due to transient or Byzantine faults affecting an application system. Implementation of this approach is also easy. A test program's present state is compared with its pre-computed state also in order to detect state transition - fault also. ESVP is intended to be suitable for a computer- based process monitoring system.