Basic Computing Arts was issued patent 3931504 in 1973 which describes computing the statistical base (or checksum) of problem steps loaded from a library device, comparing the resulting value with a value in a sum file, and taking appropriate action if a difference is found.

A system and method for controlling program execution by using a list of hash values. Specifically calls out loading a library as one method of loading executable code.

Windows XP Software Restriction Policies can regulate the loading of software modules based on, among other things, a hash of the executable file.

Microsoft's patent on Windows XP software restriction policies