ZkVaccination

This project presents a solution to share your vaccination correctness in an easy and private way. With this solution, authorities will can check on chain the correctness of a vaccination. No more photoshop changing the COVID certificate or faking PCR It mainly has to functions:

• addVaccination: can only be called by a certified hospital (issuer). It registers a new vaccination to the user. It increases the vaccination count of the user and sets the last vaccination time at the moment of the registration.
• checkVaccination: should be called by an authority (verifier). It is used to verify on-chain the correctness of user's vaccination. It is only correct if the user has 2 vaccinations or more and if the last vaccination is from less than 9 months.

Also a set of tests have been implemented, coverage included :D

This project uses SnarkyJS to build and deploy easily on MINA network. The project is build with typescript using SnarkyJS libraries to define the smart contracts to deploy to the mina protocol. SnarkyJS was super useful to perform arbitrarily-complex computations off chain while incurring only a flat fee to send the resulting zero-knowledge proof to the chain for verification of this computation, as opposed to other blockchains that run computations on chain and use a variable gas-fee based model. Testing is done with Jest