Audited use of a cryptographic key
View Patent ↗Methods and apparati for auditing uses of cryptographic keys. In a method embodiment of the present invention, a set of audited uses for a cryptographic key is defined; the key is generated inside a protected execution environment of a digital computer; all software and firmware that is usable in the execution environment to access the key is demonstrated to an auditor; and, for each audited use of the key, a non-tamperable audit record describing said use is released.
1. Method for auditing use of a cryptographic key, said method comprising the steps of:
defining a set of audited uses for the cryptographic key;
generating the key inside a protected execution environment of a digital computer;
demonstrating to an auditor all software and firmware usable in the execution environment to access the cryptographic key;
demonstrating to an auditor that the cryptographic key is protected in the protected execution environment;
for each audited use of the cryptographic key, releasing a non-tamperable audit record describing said use of the cryptographic key;
inputting a public verification key of an auditor into the protected execution environment; and
taking the following actions prior to any audited use of the cryptographic key:
sending a description of the use of the cryptographic key to an auditor; and
verifying a digital signature of an auditor inside the protected execution environment using the public verification key of an auditor.