Re:Programming Zero Knowledge Proofs: From Zero to Hero
by macawfish on Monday September 02, 2024 @04:28PM
(#41428534)
I've also found that it's hard to sort out the blockchain hype from the interesting stuff, but trust me, ZK proofs are amazing and have applications way beyond blockchain. They're a new primitive in a space that's being called "programmable cryptography". Some other interesting building blocks in this space are secure multi-party computation (MPC) and fully homomorphic encryption (FHE).
Forgive my simplified/contrived examples but you can do a whole lot more with zero knowledge proofs than you can do with just hashes and access tokens, stuff that has nothing to do with blockchain.
For example:
1. An individual receives a contract via email and needs to confirm that it contains a specific clause ("The client agrees to pay $10,000 within 30 days").
2. However, they don’t want to reveal the rest of the contract to the verifier.
3. The individual uses a ZKP that proves two things:
a. The contract is digitally signed by the specific email domain of the sender (e.g., @example.com).
b. The contract contains the specific clause matching a regular expression pattern (e.g., The client agrees to pay \d+\ within \d+ days).
4. The verifier receives the proof, checks its validity, and confirms both the signature and the presence of the clause, all without seeing the full document.
Here's another one:
1. A passenger needs to prove to a ride-sharing app that they are within a specific pickup zone to request a ride.
2. The passenger doesn’t want to broadcast their exact location due to privacy concerns. They're using a device that can attest to the authenticity of their location.
3. The passenger uses a ZKP that proves:
a) Their current location is within the allowed pickup area.
b) Their mobile device has provided an attestation that their given location wasn't spoofed.
4. The ride-sharing app verifies the proof, allowing the ride request, while the passenger’s precise location remains private.
5. The rider can choose to share their exact location with a nearby driver when the time comes, but doesn't need to broadcast their exact location to all drivers.
And yet another one:
A user wants to prove that their edited photo originated from an actual physical camera capable of signing images.
For each consecutive edit, the editing software creates a proof that the input image is either an original signed image or comes with a ZK proof that it's derived from a sequence of edits originating from a signed input image. ZK proofs can be combined in such that we can turn a large number of proofs with dependencies on one another into a single, quickly verifiable proof. So in the end you can quickly verify that a heavily edited image does indeed originate from a trusted camera.
Forgive my simplified/contrived examples but you can do a whole lot more with zero knowledge proofs than you can do with just hashes and access tokens, stuff that has nothing to do with blockchain.
For example:
1. An individual receives a contract via email and needs to confirm that it contains a specific clause ("The client agrees to pay $10,000 within 30 days").
2. However, they don’t want to reveal the rest of the contract to the verifier.
3. The individual uses a ZKP that proves two things:
4. The verifier receives the proof, checks its validity, and confirms both the signature and the presence of the clause, all without seeing the full document.Here's another one:
1. A passenger needs to prove to a ride-sharing app that they are within a specific pickup zone to request a ride.
2. The passenger doesn’t want to broadcast their exact location due to privacy concerns. They're using a device that can attest to the authenticity of their location.
3. The passenger uses a ZKP that proves:
4. The ride-sharing app verifies the proof, allowing the ride request, while the passenger’s precise location remains private.5. The rider can choose to share their exact location with a nearby driver when the time comes, but doesn't need to broadcast their exact location to all drivers.
And yet another one:
A user wants to prove that their edited photo originated from an actual physical camera capable of signing images.
For each consecutive edit, the editing software creates a proof that the input image is either an original signed image or comes with a ZK proof that it's derived from a sequence of edits originating from a signed input image. ZK proofs can be combined in such that we can turn a large number of proofs with dependencies on one another into a single, quickly verifiable proof. So in the end you can quickly verify that a heavily edited image does indeed originate from a trusted camera.