I would like to print pre-signed documents with a verifiable OTP on it.
I'm a web/system developer, crypto and security enthusiast. Somehow, I'm now the head of HR in a hotel in Congo. As an IT guy, I want to do the most with less work, so for instance I've developped an intranet that automatically generates the required certificates (employer's certificates, training certificates, ...), with my own signature + company's stamp on it, as PDF.
For now, I'm the only one authorized to generate "pre-signed" documents, but it's not hard to scan and crop a document to extract this area, so I'm looking for a way to paste (inside the signature area) something like an OTP to be able to control the validity of a document.
For instance, we assign a given ID to a document, and assign a given OTP-like to the signature on that same document. Then, for anyone in the company, it will be possible to check on the intranet a given ID which will lead to the associated OTP (or the other way around).
Now my question is what would be the best non guessable way to implement it?
UUIDs and/or a
cryptographic signature seem to be logical choices, but too long (to paste in the signature area) IMO. Any idea?
Thank you for your help.
PS: I precise "Congo" above because there is currently NO LAW about numeric documents. Everything have to be printed, signed and aknowledged.