Zero Knowledge

Zero knowledge is a technological advancement within cryptography that can be used to create more private and truly personalized web applications. The term “zero knowledge” may not sound familiar to most but its underlying concepts can be easily understood with real-life examples. The following provides an introduction to zero knowledge and will help you to better understand what zero knowledge is.

Zero knowledge proofs are cryptographic protocols that enable two parties to prove and verify something without revealing how it is true. As such, zero knowledge proofs help one party (“the prover”) to provide proof of something that the other party (“the verifier”) can verify – without showing how it is true.

The cryptography underlying zero knowledge proofs ensures that neither the verifier nor any other party learns why the statement is true. At the same time, all parties receive a confirmation that the statement is true.

This may sound complex at first sight but a real-world example quickly helps to break down the idea behind zero knowledge proofs. Let’s have a look how zero knowledge proofs can be utilized to verify a user’s age.

Let’s assume that a given application restricts its service to users above the age of 21. By using Aleo and the zero knowledge proofs it provides, users could sign up to the application and verify that they are older than 21 without having to reveal any personal data such as their actual age or their date of birth. The application will only learn that the new user is above 21 but will not know how old the users is or when they were born.