1433 results about "Cryptography" patented technology

Secure computation environments are protected from bogus or rogue load modules, executables and other data elements through use of digital signatures, seals and certificates issued by a verifying authority. A verifying authority-which may be a trusted independent third party-tests the load modules or other executables to verify that their corresponding specifications are accurate and complete, and then digitally signs the load module or other executable based on tamper resistance work factor classification. Secure computation environments with different tamper resistance work factors use different verification digital signature authentication techniques (e.g., different signature algorithms and / or signature verification keys)-allowing one tamper resistance work factor environment to protect itself against load modules from another, different tamper resistance work factor environment. Several dissimilar digital signature algorithms may be used to reduce vulnerability from algorithm.

Techniques for utilizing security criteria to implement document retention for electronic documents are disclosed. The security criteria can also limit when, how and where access to the electronic documents is permitted. The security criteria can pertain to keys (or ciphers) used to secure (e.g., encrypt) electronic files (namely, electronic documents), or to unsecure (e.g., decrypt) electronic files already secured. At least a portion of the security criteria can be used to implement document retention, namely, a document retention policy. After a secured electronic document has been retained for the duration of the document retention policy, the associated security criteria becomes no longer available, thus preventing subsequent access to the secured electronic document. In other words, access restrictions on electronic documents can be used to prevent access to electronic documents which are no longer to be retained.