US Patent 9882720 Data loss prevention with key usage limit enforcement

In a distributed system, a computer system responsible, at least in part, for complying with a cryptographic key usage limit for a cryptographic key, obtains results of cryptographic operations generated based at least in part on the cryptographic key and transmits the obtained results over a network. The computer system digitally signs the results and provides the results with digital signatures of the results. Another device intercepts the results and allows the results to proceed to their destination contingent on successful validation of the digital signature.