Patent attributes
An apparatus includes a memory and a hardware processor. The memory stores a private encryption key. The processor intercepts a first transaction request from a user, communicates a first recertification request to a certificate authority that issued the private encryption key, and receives, from the certificate authority, a first message indicating that the private encryption key is valid for use. In response to the first message, the processor generates a first digital signature using the private encryption key, generates a first non-repudiation message comprising the first digital signature and the first message, generates a second message comprising the first transaction request and the first non-repudiation message, and communicates the second message to a server to process the first transaction request.