Email Proofs Architecture

Email proof sequence flow

Generating and ZK-proving an Email Proof consists of the following steps:

1. The received email MIME file is extracted from the email client.
2. The preverifyEmail in the SDK prepares the UnverifiedEmail struct that is ready to be sent to the Prover Contract.
   • Performs basic preverification - checks if the DKIM-Signature header is present.
   • Calls the DNS Notary to get the verification data of the sender's domain.
   • Note that all these steps can be performed without the vlayerSDK.
3. The DNS Notary fetches the public key used to sign the email from a number of DNS providers, compares the results, and if there's a consensus among them, signs the result with its private key.
4. The DNS record with it's signature and the raw email together form the UnverifiedEmail struct.
5. A v_call is made to the vlayer server with the UnverifiedEmail struct as well as the rest of the Prover contract arguments as calldata, chain ID, and the address of the deployed Prover contract.
6. The Prover contract must use the EmailProofLib, where the DNS Notary public key is verified. The EmailProofLib library calls the Repository contract to verify whether the DNS Notary public key is valid. It also checks the signature TTL against the current block timestamp.
7. Next, the EmailProofLib contract calls the email_proof.verify(UnverifiedEmail) custom precompile (see Precompiles), which validates the Email Proof, parses the email MIME file, and returns a VerifiedEmail.
8. If the verification is successful, the EmailProofLib returns the VerifiedEmail struct to the Prover contract. Otherwise, it will revert.