Sounds more like a copyright than a patent.
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Trust me, the patent bills from the solicitors underscore it's patent credentials. And the annual fees.
Pretty close, actually, and some of it is not your fault, as I obfuscated a bit of the definition by deploying an analogous technology. "
It was originally developed for DOS, which made it compatible with every MS operating system since (and network protocols from Banyan Vines to LANtastic).
It compares the disk image of the protected application with the one that is running in memory to see if there is a hot-viral code trying to alter the protected applications behaviour (like pushing it through a decompiler, for example, to reverse engineer what it does) and quits if the check fails. It protects itself with encryption, so that it has a message digest to identify anyone altering even one bit, as well as an encrypted footprint, to prevent anyone reading the application or the protection (thus making circumvention that much harder).