A probabilistic method of detecting viral intrusion into an original computer file is disclosed. In the method, a protection file is first created. In the preferred embodiment, the protection files is created by generating a test string. The test string is compared to the original computer file and is...http://www.google.com.au/patents/US5448668?utm_source=gb-gplus-sharePatent US5448668 - Method of detecting changes to a collection of digital signals
