Many people are puzzled: After @CetusProtocol was hacked, Sui's validator network coordinated to "freeze" the hacker's address, recovering $160 million. How exactly was this done? Is decentralization a "lie"? Let's analyze this from a technical perspective:
Cross-chain bridge transfer: After the successful hack, the hacker immediately transferred some USDC and other assets to other chains like Ethereum through a cross-chain bridge. These funds cannot be recovered because once they leave the Sui ecosystem, validators are powerless.
Portion remaining on Sui chain: A significant amount of stolen funds still remain in the hacker's Sui address. These funds became the target of "freezing".
According to the official announcement, "Many validators have identified the stolen fund addresses and are ignoring transactions from these addresses".
—How was this specifically implemented?
1、Transaction filtering at validator level—simply put, validators collectively "play blind":
- Validators directly ignore transactions from the hacker's address at the mempool stage;
- These transactions are technically completely valid, but just not packaged onto the chain;
- The hacker's funds are thus "soft confined" in the address;
2、Key mechanism of Move object model—Move language's object model makes this "freezing" possible:
- Transfer must be on-chain: Although the hacker controls a large number of assets in the Sui address, to transfer these USDC, SUI and other objects, they must initiate a transaction and have it packaged and confirmed by validators;
- Validators hold life-and-death power: If validators refuse to package, the objects will never move;
- Result: The hacker nominally "owns" these assets, but actually has no way to use them.
It's like having a bank card, but all ATMs refuse to serve you. The money is in the card, but you can't withdraw it. With continuous monitoring and interference from SUI validator nodes (ATMs), tokens like SUI in the hacker's address will be unable to circulate, and these stolen funds now seem "destroyed", objectively creating a "deflationary" effect?
Of course, in addition to temporary validator coordination, Sui might have preset a denial list function at the system level. If so, the process might be: relevant authorities (like Sui Foundation or through governance) add the hacker's address to the system deny_list, and validators execute according to this system rule, refusing to process transactions from blacklisted addresses.
Whether through temporary coordination or system rule execution, this requires most validators to act uniformly. Clearly, Sui's validator network power distribution remains too centralized, with a minority of nodes able to control key network decisions.
The over-centralization of Sui's validators is not unique to PoS chains—from Ethereum to BSC, most PoS networks face similar validator centralization risks, but Sui has exposed the problem more obviously this time.
—How can a network claiming to be decentralized have such a strong centralized "freezing" capability?
More critically, Sui officially stated they would return the frozen funds to the pool, but if validators truly "refuse to package transactions", these funds should theoretically never move. How will Sui achieve this return? This further challenges Sui's decentralization characteristics!
Could it be that beyond a few centralized validators refusing transactions, the official side even has system-level super permissions to directly modify asset ownership? (Sui needs to provide further "freezing" details)
Before specific details are disclosed, it's necessary to discuss the trade-offs around decentralization:
Is emergency intervention that sacrifices some decentralization necessarily bad? If a chain does nothing when facing a hack, is that truly what users want?
What I want to say is that while naturally no one wants money to fall into hackers' hands, what makes the market more worried is that the freezing standard becomes completely "subjective": What counts as "stolen funds"? Who defines this? Where are the boundaries? Today it's freezing hackers, who will it be tomorrow? Once such a precedent is set, the public chain's core anti-censorship value is completely bankrupt, inevitably damaging user trust.
Decentralization is not black and white. Sui has chosen a specific balance point between user protection and decentralization. The key issue lies in the lack of transparent governance mechanisms and clear boundary standards.
Most blockchain projects are currently making such trade-offs, but users have the right to know the truth, rather than being misled by the "completely decentralized" label.
