Understanding Zero-Knowledge Proof in Digital Identity
A proof that uses special cryptography and a link secret to support selective disclosure of information about a set of claims from a set of credentials. A Zero-Knowledge Proof (“ZKP”) provides cryptographic proof about some or all of the data in a set of Credentials without revealing the actual data or any additional information, including the Identity of the Prover. (LIVING DOCUMENT – Sovrin Glossary V3 Living Community Version, n.d.)
Let’s see how it works. Mary is a subscriber of YuTru and has been conducting her business online. Recently, Mary bought a car and wants to obtain her driving license. Mary submits her online application to obtain a license from the Motor Licensing company, another relier of YuTru.
The relier (Motor Licensing company) only needs to know if Mary is of age to apply for a driving license. Here the relier only requests her eligibility before issuing a license. Without disclosing Mary’s date of birth or address, the Motor Licensing company only receives a “yes” or “no”. Since Mary is over the age of 18, the relier receives confirmation that she is of eligibility and a license is issued.
Therefore, Zero-Knowledge Proof provides proof while ensuring user data privacy.
Key Features of Zero-Knowledge Proofs
- Completeness – If the statement is true, the relier will be convinced by the issuer.
- Soundness – If the statement is false, the relier will not be convinced by any issuer.
- Zero-Knowledge – The relier learns nothing other than the fact that the statement is true.
Benefits of Zero-Knowledge Proofs
- Enhanced Privacy
By not revealing any information during the verification process, Zero-knowledge proof protects users’ privacy, making it ideal for sensitive applications like medical records and financial transactions.
- Improved Security
Since no actual data is transmitted during the proof, the risk of data interception and misuse is minimised, offering a robust layer of security against cyber threats.
- Regulatory Compliance
Zero-knowledge proof can help organisations comply with privacy regulations like the General Data Protection Regulation (“GDPR”), by minimising the amount of personal data they need to store and process.