zk-SNARK: Zero-Knowledge Succinct Non-Interactive ARgument of Knowledge

What is zk-SNARK

Blockchain is the solution to many real-world problems, but blockchain has some limitations, and with time, these limitations can become issues for the users. It can harm not only the blockchain network but also the ecosystem participants.

zk-SNARK stands for Zero-Knowledge Succinct Non-Interactive Argument of Knowledge, a digital certificate that can prove anything without disclosing the information, and using zk-SNARK MINA protocol, creating a succinct blockchain of 22kb.

Let’s understand how zk-SNARK helping MINA protocol to create a succinct blockchain of 22kb, but before that let’s understand how mining works in Bitcoin. So when you initiate a transaction by sending some Bitcoins to your friend, Bitcoin never virtually transfers, but the owner of the Bitcoin changed. The Bitcoin remains in the network, but your data goes into a block when you initiate the transaction. That block stands in a queue for verification, then between miners, a war of computer power started where the powerful computers mostly win.

During this war, computers verify that block’s data and find out whether the transaction you want to do is legit or not by checking the genesis of that Bitcoin. but zk-SNARK can help miners by saving their time and efforts because they just need to verify one thing which is zk-SNARK.

So zk-SNARK can be taken as a virtual certificate that generates whenever a new block is produced by replacing the latest one. Suppose a blockchain can create three blocks like block 1, block 2, and block3 for the first block, zk-SNARK 1 generated with size 22kb, then for the second block zk-SNARK 2 generate of size 22kb and zk-SNARKS 1 + zk-SNARK 2 combine to generate a single zkSNARK which is 22kb. After block3 producing zk-SNARK3 of 22kb, it combines with the exiting zk-SNARK of size 22kb to again create a single zk-SNARK of size 22kb. Hence, as a miner, you don’t need to verify block 1,2,3, but you only need to verify the final zk-SNARK, which will save your time, efforts and energy.

Benefits

The best benefit of the zk-SNARK is that it can reduce the size of the blockchain to 22kb only. So the size of the blockchain will never increase, so we will never face any blockchain size-related problems, and every light-end device can be a node of the blockchain to benefit from all the features that blockchain provides.

zk-SNARK helps provide data protection, so when you connect to a third party, it never discloses your data but allows you to prove anything you want. For example, suppose you visit for account opening somewhere on the internet, and that party asks you for your data. Then instate of data, you provide zk-SNARK of your data to prove that you have a real name and address but don’t need to disclose. SNARK powered applications can help us protect thousands of data floating out from your family’s devices.

Improvements / R&D

I think there's still a next layer of incremental improvements to ZK-SNARK tech that are not so much zero-to-one, but could still lead to huge gains that we are not seeing yet. Specifically:

• ZK-SNARK'd VMs (including the EVM);
• SNARK-friendly hash functions;
• SNARK-friendly aggregate signatures.

Once we have this, we could just SNARK the entire Ethereum state transition function, and have fully verifying light clients. But further on, I personally am most excited about fully homomorphic encryption and obfuscation. Obfuscation has seen formally provable proposals for the first time last year, and FHE has been around for a while and is consistently improving.