WEB FREE #8: Zero-Knowledge Proofs

"Zero-knowledge proof." What sounds like an average college exam experience is in fact one of the most powerful and promising cryptographic techniques in existence. The new WeSendit will also make use of ZKP, so it's about time to explain the concept in more detail. Let's dive right into the world of provers, verifiers, and believers.

What are Zero-Knowledge Proofs?

Zero-knowledge proofs (ZKP) allow one party (the prover) to prove to another party (the verifier) that they know a particular piece of information without actually revealing the information itself. In other words, ZKPs allow you to convince someone else of the truth of a statement without revealing any information beyond the actual truth of the statement.

The zero-knowledge proof concept was introduced in 1985 and has gained popularity and significance with the rise of blockchain technology. Today, sophisticated ZKP are used for authentication, privacy protection, and identification purposes.

The two main types of ZKP are:

• Interactive zero-knowledge proofs — require a repeated form of dialogue between prover and verifier to complete a proof.
• Non-interactive zero-knowledge proofs — only need one initial message from the prover to the verifier. The latter can then validate the proof without further interaction.

How do zero-knowledge proofs work?

Imagine a hidden picture puzzle for children — a train station scene full of people, and you and your friend are both supposed to find the location of the red suitcase. You tell your friend you know the location, but he does not believe you. How can you prove that you know the location without giving it away?

You simply cut out a very small area around the suitcase and show it to your friend. Your friend now knows that your statement was correct — yet he still does not know the actual location of the suitcase. He does not get access to the information itself, but you still managed to prove that you "own" it. That is how things work with zero-knowledge proofs — plus a few more formulas and computations.

What are the main benefits of zero-knowledge proofs?

• Strengthened privacy: ZKP can validate the truthfulness of an information without the need to reveal the information itself — especially valuable for healthcare records, patient data, financial info, and personal information.
• Improved security: By eliminating the need for intermediate parties, zero-knowledge proofs increase the security of blockchain transactions, especially when it comes to proving ownership.
• Greater efficiency: Sophisticated ZKP minimize the need for processing power and additional computation, lowering costs and speeding up the entire verification process.
• Decentralized trustless systems: Zero-knowledge proofs enable trustless verification by providing mathematical proofs of correctness — making possible the "trustless systems" that blockchain technology seeks to create.

Conclusion: From zero to hero!

Zero-knowledge proofs have the potential to fulfill one of blockchain's most important promises: to enable a trustless system in which your personal information remains safe at all times. The possible use cases are breathtaking and many organizations, including WeSendit, are working to build powerful applications. The era of zero-knowledge proofs has only just begun — and they will have a major impact on file transfer and storage.