Why Vitalik is pushing for zk-SNARK, an important tool for solving blockchain's complex problems.

At the EDCON conference in Montenegro, @VitalikButerin explained the technical challenges that the Ethereum network faces in terms of scalability, privacy, and security, and concluded that zk-SNARK will be as important as blockchain in the next 10 years. What exactly is zk-SNARK that Vitalik Buterin is promoting? What current blockchain problems can zk-SNARK technology solve? In the following thread, let's explore together.

SNARK, short for succinct non-interactive argument of knowledge, is a proof system constructed through mathematical algorithms. Its core is to enable verifiers to verify the correctness of data without knowing the original data. The implementation process involves complex technologies such as verifiable circuits, elliptic curve cryptography, hash functions, and encryption algorithms. However, we will not delve into too many details here.

Due to the fact that SNARK can compress raw data into an extremely small proof to verify the correctness of its input data, combined with the technical foundation of zk zero-knowledge, zk-SNARK can greatly demonstrate its advantages in blockchain scalability, privacy, security and other aspects. Especially after Ethereum adopted the Merkelized Abstract Syntax Tree (MAST) algorithm in 2018, zk-SNARK can be directly integrated into the Ethereum system to solve the current bottleneck problem of the Ethereum network.

This is why the zk-SNARK technology, which originated from @Starknet, is expected to achieve greater success, despite the fact that the native zk-STARK technology can handle more complex computing problems (avoiding quantum computing attacks, etc.). Especially, some of the blockchain paradoxes that have puzzled everyone can be effectively solved by switching to the underlying zk-SNARK, such as: protecting privacy from potential money laundering by hackers, and the centralization interference problem that social recovery cannot escape, etc.

First, let's talk about scalability. The zk-rollup technology is highly advanced compared to op-rollup and is an ultimate solution for Ethereum Layer 2. Op-rollup assumes all transactions are optimistic and undergoes a 7-day fraud proof challenge period after being submitted to the chain, while zk can quickly and securely ensure the legitimacy of each transaction on the chain based on mathematical algorithms. (For details, please refer to a previous Thread).

Here, zk-SNARK solves a paradoxical problem of scalability and centralization in Ethereum. Although the op-rollup solution is more mature in practical scenarios, there is still a potential risk of centralization in the sequencer and optimistic challenge verification process. We can certainly be "optimistic", but to achieve absolute decentralization in rollup, SNARK is necessary.

Let's talk about privacy. Based on the current context of blockchain technology, developing privacy technology would lead to a logical paradox. Would privacy ultimately become a wedding dress for hackers? However, if based on zk-SNARK, a Proof of Innocence (POI) scheme can be developed to ensure that users can enter and exit funds through privacy while avoiding the use of illegal elements for malicious purposes. Specifically, POI technology can be applied to protocols similar to Tornado.

POI technology provides each user with a digital fingerprint based on blockchain state history records and private key generation. When hackers attempt to launder money through Tornado's mixing transaction pool, if the withdrawal request address and deposit address provided by the hacker are contradictory (with different private keys), the transaction will be intercepted and returned to the original mixing address. This means that the hacker's unidentified assets cannot escape tracking through the mixing system.

Of course, as mentioned in V's speech, you can also directly build an exclusion list Merkle tree, which is equivalent to adding a blacklist mechanism to the Tornado protocol. Normal user deposits that are not on the list can generate innocent proofs and use Tornado normally, otherwise it is the opposite. Although blacklisting is effective, there is a centralization risk. Personally, I think it is more meaningful to block transactions where the input and output private keys do not match.

Lastly, let's talk about the security issue of third-party anti-censorship paradox. The Social Recovery feature is undoubtedly a path that blockchain must take for mass adoption. However, as we can see from the community protests that @Ledger faced when opening this feature, recovery cannot be based on the premise of centralization of third parties. The zk-SNARK technology can precisely solve this problem.

In simple terms, when a user generates multiple private key fragments, the fragments can be encrypted and zk-SNARK proof system can be used to generate proofs, which can then be distributed to trusted institutions or friends.

If the user loses their private key, they can request a third party to provide fragment data proofs, and then use zk-SNARK to verify the accuracy of these proofs, thereby achieving the function of social recovery without revealing private key fragments.

After fully understanding the above content, it is not difficult to see the importance of zk-SNARK technology for blockchain systems. It can solve various Ethereum network development paradox problems such as scalability and centralization, privacy and malfeasance, security and anti-censorship. Therefore, V God said that zk-SNARK will be as important as blockchain in 10 years, and maybe Ethereum will also be zk-SNARKized in the future. Well, zk-SNARKS Rule Everything Around Me.

Thank you @TommyDeng_DAO for summarizing the content of the Black Mountain V God Conference speech for the first time, as well as providing a large number of wonderful illustrations. The above technical thinking is only open thinking for reference, and everyone is welcome to discuss and criticize.

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