Entrada Solutions
nEmailVeriChain
nEmailVeriChain
Pavan Ranganath
August 7, 2023
7:15 pm

Revolutionizing Email Verification: Harnessing Blockchain and Zero-Knowledge Proofs

In an era where security and privacy have taken center stage, we're pioneering a breakthrough approach to email verification by integrating blockchain technology and Zero-Knowledge Proof (ZKP). Renowned for its decentralized, secure, and immutable nature, blockchain provides a robust platform for reliable email verification. When coupled with ZKP, an advanced cryptographic technique that allows one party to prove that they know certain information without revealing it, our system elevates user privacy to unprecedented levels. By embracing these cutting-edge technologies, we offer a more secure, transparent, and traceable email verification process that significantly enhances user privacy.

Details:

  1. Claim Submission: The journey begins with a submitter initiating the process. The submitter sends a claim to the blockchain via a smart contract. This claim could be a piece of information or a statement that requires verification.
  2. Verified Attester: Once the claim is submitted, it needs an attestation from a trusted entity. This entity, the attester, is responsible for verifying the authenticity of the claim.
  3. Claim Verification: After receiving the claim, the attester performs the necessary verification steps. These might involve validating evidence, conducting research, or applying predefined criteria to determine the validity of the claim.
  4. Attestation: Upon completion of the verification process, the attester generates an attestation that confirms the claim's validity.
  5. Attestation Submission: This attestation is then submitted back to the blockchain via the smart contract. The smart contract records the attestation, associating it with the original claim and the respective submitter.
  6. Blockchain Immutability: Once submitted to the blockchain, the attestation becomes an immutable record. It cannot be altered or tampered with, ensuring a secure, transparent audit trail.
  7. Zero-Knowledge Proof (ZKP): This is where ZKP comes in. The submitter and verifier engage in a protocol that enables the submitter to prove a claim's validity to the verifier without revealing any specific information about the claim. This cryptographic technique ensures the utmost privacy and confidentiality.
  8. ZKP Generation: Once the attestation process is complete, the system generates a proof based on successful attestations. This proof serves as evidence that the claim has passed the attestation process and is reliable.
  9. Proof Presentation: The system presents the generated proof to the submitter.
  10. Claim Verification by Third Parties: Any third party can use this proof to independently confirm the claim's authenticity. They can do this without needing to rely on the original data, further enhancing privacy and trust.

Email Authentication  / Verification:

Email authentication and verification are important mechanisms to ensure the authenticity and integrity of email messages. DKIM, SPF, DMARC, and ARC are different protocols and technologies used for email authentication and verification.

  • DKIM (DomainKeys Identified Mail): DKIM uses asymmetric cryptography to add a digital signature to the header of an email message. The sending domain generates a pair of cryptographic keys: a private key kept secret by the domain owner and a public key that is published in the domain's DNS records. The private key is used to generate the signature, and the public key is used by the recipient's server to verify the signature. By verifying the signature, the recipient can confirm that the email originated from the claimed domain and that it hasn't been tampered with during transit.
  • SPF (Sender Policy Framework): SPF is an email authentication protocol that helps detect forged sender addresses in email messages. It allows domain owners to specify which mail servers are authorized to send email on behalf of their domain. By checking the SPF record published in the domain's DNS, the recipient's server can verify if the sending server is allowed to send emails to the domain. SPF helps prevent email spoofing and reduces the chances of phishing and spam.
  • DMARC (Domain-based Message Authentication, Reporting, and Conformance): DMARC builds upon DKIM and SPF to provide a comprehensive framework for email authentication and policy enforcement. It allows domain owners to specify a policy in their DNS records that instructs the recipient's server on how to handle emails that fail authentication checks.
  • ARC (Authenticated Received Chain): ARC is an extension to the existing email authentication methods, designed to address issues with email forwarding and mailing lists. When an email is forwarded or passes through a mailing list, the original DKIM signature may be invalidated or modified. ARC preserves the original DKIM signature by adding an additional signature to the email header. Subsequent email servers can then 

Note: While DKIM, SPF, DMARC, and ARC provide important layers of email authentication and verification, it's important to note that they are not foolproof. Implementing these protocols is a significant step toward enhancing email security, but it should be integrated with other security measures such as encryption, spam filtering, and response to potential threats.

Generation of ZKP for the email address

  1. Signature Generation: The user, who wishes to verify their email address, uses their Ethereum wallet to sign their email address (have this info during verification of Ethereum address). This creates an ECDSA signature with two components, `R` and `S`, and the recovery parameter `V`. 
  2. Attestation Signature Generation: Next, an attester verifies the user's email and then signs the the email address. The attestation also generates an ECDSA signature (`attestationR`, `attestationS`, and `attestationV`).
  3. Submission to the Circuit: Once both signatures are created, the system submits the hashed email, their signature (`signatureR`, `signatureS`, `signatureV`), the attester's signature (`attestationR`, `attestationS`, `attestationV`), and the public keys for both the user and the attester (`publicKeyX`, `publicKeyY`, `attesterPublicKeyX`, `attesterPublicKeyY`) to the zero-knowledge proof system with the given circom circuit.
  4. Email Hash Verification: When the inputs are received by the zero-knowledge proof system, the Circom circuit first checks that the hashed email submitted matches the hash computed within the circuit. If they match, the circuit proceeds to verify the signatures.
  5. User Signature Verification: The circuit verifies that the user's ECDSA signature (`R`, `S`, and `V`) corresponds to the hashed email and the user's public key. If the signature is valid, it proceeds to the attestation verification.
  6. Attester Signature Verification: The circuit then verifies that the attester's ECDSA signature (`attestationR`, `attestationS`, and `attestationV`) also corresponds to the hashed email and the attester's public key. If the attestation is valid, the circuit completes its checks.
  7. Proof Generation: Once all checks are completed, the circuit will produce a proof that verifies the authenticity of both the user's signature and the attester's signature on the hashed email. This proof can be shared with others, and those parties can verify the proof without having to see the user's email, maintaining the user's privacy.
  8. Proof Distribution: The user then shares this proof along with the necessary public inputs with any third party that needs to verify their email attestation.
  9. Proof Verification: The third-party recipient of the proof uses a zk-SNARK verification function to check the proof. The inputs to this function are the proof itself and the public inputs (`hashedEmail`, `publicKeyX`, `publicKeyY`, `attesterPublicKeyX`, `attesterPublicKeyY`). The verification function will return true if the proof is valid and false if it's not.

Conclusion

Our innovative fusion of blockchain technology and Zero-Knowledge Proofs brings about a new era in email verification. It provides a secure, transparent, and decentralized solution that protects user privacy and enhances trust. As we continue to evolve our system, we are excited about the potential of these technologies and look forward to the future of email communication.

Category : Blockchain Web3.0 ZKP