Q: Once a large enough quantum computer exists, what does that do to the past?
- Basically, there are two things we do with cryptography: hiding information and integrity or proof. The thing with hiding information is that you’re a hostage to time: if the quantum computer comes along, you can’t hide the info but you can rely on old proofs.
Q: What’s immediately next? Can this group help?
- We’d like more users: we have it released in a restrictive open source license, and also through commerical licenses.
Q: The last time you mentioned proofs you were referring to interactive proofs. These seem to be not the same, these are static proofs that prove that an interactive proof was performed?
- Yep. It’s called a Fiat-Shamir transform. The interactive kind were a series of challenges and responses that made it very unlikely that the responder could be bluffing the entire time. In this case, the proof is a hash of all of the things that you’re proving and have to satisfy the hash at hundreds of locations.
- This makes it practical: a 2000 byte proof can prove arbitrarily large computations took place.
Q: In the smart contract setting, you need the full contract plus the proof on chain to manage. How are you enforcing this if the contract is not on the blockchain?
- Yes, you can prove that computations tooks place elsewhere as long as you know the identity of the smart contract.
- The proof is based on proving that a program with a certain ID ran a computation and returned a certain result: you would need this identifier but you could then later generate a proof that that program returned something you’re looking for.