Implement a Forced-PGP system in a virtual store that already exists.

I'm finishing my degree work for my specialization my project consists of an online store that only accepts cryptocurrencies as a payment method, the site doesn't use javascript because must be TOR compliant, the store sells digital and physical items, I want to offer users a high degree of encryption for their transactions and communications, for therefore I want to implement a forced-PGP system in all activities within the store. The project requires an expert in PGP and GPG to carry out this project.