https://open.spotify.com/episode/3cemC6cxTLqgFtuVdRHYgf?si=PBU7jdmCR9i_AIVR49icrw&nd=1

A very good intro podcast to zk by the developer of starknet.

ZK, zero knowledge proof is a very also tool for many applications. The most brought up topic about zk is zk rollup on ETH. Fundamentally, blockchain is really not good at any general storage or computation, that's why programs on blockchain are called smart contract. In the long term, I still don't see the system built on blockchain could or should be used to handle too much general computation. What zk rollup brings to the system is only cheap computation with minimum accessible storage (so don't expect any server software running on it).

Zk is basically proof that you know something without actually revealing the information. The basic zk validity proof roll up process to L1 is: 1. the sequencer(s) aggregates all transactions into a block 2. the prover computes the block with a special paradigm and generate the results and the validity proof of the computation. 3. the prover submits the state difference/result and the proof to L1, there will be a verifier on L1 to verify those results.(verify takes very little computational resources)

This process separates the computation from the blockchain. It's crucial since, computation will be run on all nodes on L1, not scalable at all. Now you can only verify the results, you can also bundle them to further decrease the computational requirements. As comparison to optimistic rollup, which assumes all transactions processed are valid until the fault proof process, zk roll up doesn't have to wait for the days of roll up confirmation to L1.

Zk proof is the proof of the execution of transactions, so that is blockchain agnostic, meaning it could verify another chain from one chain. One major application is BTC <-> ETH atomic swap, without zk, you'll need some oracle (program outside the chain) to know whether the BTC address you want to swap actually did follow the swap process. Now with zk proof on the BTC chain's state change, you don't have to deal with all the problems come with the oracle. And other application is storage chain verification.

The contents in the podcast are very detailed. Some interesting topic includes why computation is cheap, but storage is not; how they went from ASIC to cpu;how the states are stored; the domain specific language to program zk.

#zk #zeroknowledge #zkproof #ETH #Blockchain #scale #scaling #AtomicSwap #BTC #rollup