@TomS, yes, we plan to introduce a verification mechanism. We considered adding a separate UUID that could be shared with a third party. It would not allow them to download the PDF from the LMS, but they would rather use it in a web form (with an API available) that would display the certificate’s metadata (learner’s name, course name, date, etc.).
Adding a QR code or a verification link is also an option; however, for PDF certificates, it means that the URL would need to be maintained indefinitely, as there would be no option to update it for existing certificates.
To prevent less technical users from tampering with the certificate contents, we encrypt each PDF file with a random password to only allow printing and extracting text from it and forbid other actions (see “TABLE 3.20 User access permissions”).