We have a certificate verification system where certificates are verified via Encrypted QR codes and NFC Tags. Can we host this data in Blockchain (Open Source/decentralized databases) without compromising Student data confidentiality but enjoying the extra security of cryptographic encryption of the type used in the blockchains. Also, I am wary about potential costs due to heavy processing of multiple verification requests some simultaneously. Could we do this by transacting under multiple blockchain addresses? And what about the costs to the persons transacting?