This image shows the tasks involved in using digital signatures and certificates.
Upload Certificate displays at the top. This is the one time uploading of each users certificate and private key to human workflow.
Below this is Create Evidence. The user creates evidence by using their private key to digitally sign a task update.
Below this is Validate. Human workflow validates the certificate used for evidence creation with the Certificate Revocation List (CRL) issued by the Certifying Authorities (CAs).
Below this is Nonrepudiation. Prove that the user generated the signature by creating the content from the user certificate and signature.