The post Vitalik Buterin Clarifies 51% Attack Limits for Users appeared on BitcoinEthereumNews.com. Buterin said a 51% attack cannot make an invalid blockchain valid. Colluding validators cannot steal user assets on-chain, he added. Risk stays if users outsource decisions to a validator set; slashing raises the cost. Ethereum co-founder Vitalik Buterin has triggered a round of discussion with his latest post about 51% attacks on blockchain. Buterin, who classified his latest post as a reminder, noted that a 51% attack “cannot make an invalid blockchain valid.” Regular reminder: A key property of a blockchain is that even a 51% attack *cannot make an invalid block valid*. This means even 51% of validators colluding (or hit by a software bug) cannot steal your assets. However, this property does not carry over if you start trusting… — vitalik.eth (@VitalikButerin) October 26, 2025 Related: Vitalik Buterin “Respects” Steak ‘n Shake’s Decision Not to Adopt ETH for Payments 51% Attack is Also Limited To further explain his view, Buterin noted that 51% validators colluding cannot steal users’ assets on a blockchain. However, he stated that this property does not carry over if blockchain users start trusting your validator set to do other things.  According to Buterin, 51% attack remains a valid risk for blockchains, considering that validators can collude to give deceptive answers, leaving users without recourse. The EigenLayer and slashing context Some respondents to Buterin’s post suspected an encrypted message in his presentation, with one such individual asking if he was referring to EigenLayer. Buterin did not give a direct reply to the question. Instead, he noted that EigenLayer relied on slashing for the exact reason of a 51% attack.  It is worth noting that Slashing does not directly prevent 51% attacks on blockchains. It rather makes them extremely costly, serving as a penalty to discourage validators that may want to engage in the process. Blockchain’s… The post Vitalik Buterin Clarifies 51% Attack Limits for Users appeared on BitcoinEthereumNews.com. Buterin said a 51% attack cannot make an invalid blockchain valid. Colluding validators cannot steal user assets on-chain, he added. Risk stays if users outsource decisions to a validator set; slashing raises the cost. Ethereum co-founder Vitalik Buterin has triggered a round of discussion with his latest post about 51% attacks on blockchain. Buterin, who classified his latest post as a reminder, noted that a 51% attack “cannot make an invalid blockchain valid.” Regular reminder: A key property of a blockchain is that even a 51% attack *cannot make an invalid block valid*. This means even 51% of validators colluding (or hit by a software bug) cannot steal your assets. However, this property does not carry over if you start trusting… — vitalik.eth (@VitalikButerin) October 26, 2025 Related: Vitalik Buterin “Respects” Steak ‘n Shake’s Decision Not to Adopt ETH for Payments 51% Attack is Also Limited To further explain his view, Buterin noted that 51% validators colluding cannot steal users’ assets on a blockchain. However, he stated that this property does not carry over if blockchain users start trusting your validator set to do other things.  According to Buterin, 51% attack remains a valid risk for blockchains, considering that validators can collude to give deceptive answers, leaving users without recourse. The EigenLayer and slashing context Some respondents to Buterin’s post suspected an encrypted message in his presentation, with one such individual asking if he was referring to EigenLayer. Buterin did not give a direct reply to the question. Instead, he noted that EigenLayer relied on slashing for the exact reason of a 51% attack.  It is worth noting that Slashing does not directly prevent 51% attacks on blockchains. It rather makes them extremely costly, serving as a penalty to discourage validators that may want to engage in the process. Blockchain’s…

Vitalik Buterin Clarifies 51% Attack Limits for Users

2025/10/29 00:11
  • Buterin said a 51% attack cannot make an invalid blockchain valid.
  • Colluding validators cannot steal user assets on-chain, he added.
  • Risk stays if users outsource decisions to a validator set; slashing raises the cost.

Ethereum co-founder Vitalik Buterin has triggered a round of discussion with his latest post about 51% attacks on blockchain. Buterin, who classified his latest post as a reminder, noted that a 51% attack “cannot make an invalid blockchain valid.”

Related: Vitalik Buterin “Respects” Steak ‘n Shake’s Decision Not to Adopt ETH for Payments

51% Attack is Also Limited

To further explain his view, Buterin noted that 51% validators colluding cannot steal users’ assets on a blockchain. However, he stated that this property does not carry over if blockchain users start trusting your validator set to do other things. 

According to Buterin, 51% attack remains a valid risk for blockchains, considering that validators can collude to give deceptive answers, leaving users without recourse.

The EigenLayer and slashing context

Some respondents to Buterin’s post suspected an encrypted message in his presentation, with one such individual asking if he was referring to EigenLayer. Buterin did not give a direct reply to the question. Instead, he noted that EigenLayer relied on slashing for the exact reason of a 51% attack. 

It is worth noting that Slashing does not directly prevent 51% attacks on blockchains. It rather makes them extremely costly, serving as a penalty to discourage validators that may want to engage in the process.

Blockchain’s Unending Evolution

In the meantime, Buterin’s reignition of the 51% attack debate triggered many questions among several blockchain community members on X, with most of their interrogations being rhetorical. For instance, one community member asked if it would be fair to say that blockchains do not guarantee veracity, and another queried if it should still be called a blockchain if 51% of validators can agree on an irregular state change.

Related: Base L2 Gets Vitalik Buterin’s Approval: “Doing Things Right” Model With Stage-1 Protection

Blockchain technology has undergone continuous evolution, with several developments adding to and modifying the basics of the original protocol since the introduction of decentralized blockchains. Notably, no single protocol currently boasts a perfect system, necessitating more advancements and collaboration among blockchains to produce more robust systems.

Q: Can a 51% attack make an invalid blockchain valid?

A: No. Full nodes keep validity rules. Majority control cannot override protocol validity.

Q: Can 51% validators steal my coins?

A: No under normal rules. They cannot move assets without valid signatures or valid transactions.

Q: Where is the real risk then?

A: In censorship, re-ordering, and reorgs, and when apps trust validator answers for extra services beyond consensus.

Q: What does slashing fix?

A: It raises the cost of collusion. It does not remove the risk. It helps deter majority abuse when validators take on extra duties.

Disclaimer: The information presented in this article is for informational and educational purposes only. The article does not constitute financial advice or advice of any kind. Coin Edition is not responsible for any losses incurred as a result of the utilization of content, products, or services mentioned. Readers are advised to exercise caution before taking any action related to the company.

Source: https://coinedition.com/vitalik-buterin-clarifies-51-attack-limits-for-users/

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‘Code Is Law’ documentary nails the drama of DeFi hacks — despite what it leaves out

‘Code Is Law’ documentary nails the drama of DeFi hacks — despite what it leaves out

Ekin Genç is DL News’ Editor-in-Chief. Opinions expressed are his own.The world was transfixed last week when thieves in construction vests at the Louvre managed to vanish with jewels worth more than $100 million. Yet when hundreds of millions vanish from decentralised finance, nobody outside crypto hears about it; you won’t see headlines of DeFi heists in mainstream media. (The Louvre heist is hefty, of course, but it still wouldn’t make it to the top 25 in crypto.)That dissonance is the starting point of Code Is Law, a new documentary about DeFi exploits:“It’s incredible, you turn on the news and see a $450 theft from a local 7-Eleven, and on the same day someone steals $25 million from a protocol and you’ll never hear about it,” pseudonymous blockchain security specialist Ogle says during the opening credits.Streaming on Amazon Prime Video, Code Is Law is probably the first serious documentary to take the woes of decentralised finance — not centralised crypto exchanges or charismatic crypto fraudsters — as its subject.“It’s done an incredible job of representing people involved as humans rather than fringe lunatics, and I’m proud I was involved in it,” Indexed Finance co-founder Laurence Day told DL News, “even if I now know more about how the sausage is made when it comes to films than I ever cared to!”Given it’s a documentary about a community that’s pretty much exclusively online, you might expect it to be un-cinematic, a story more suited to the podcast format. It does, of course, consist mostly of people explaining things, sitting in front of laptops, typing, skimming code, and wading through Discord logs. Yet the filmmakers have still managed to make the watch genuinely gripping — not just for crypto nerds, but for anyone interested in cybercrime.But those deeply involved in crypto will notice at least two major omissions — for good reasons, as one of the directors tells me.The DAO hack without the hackerYou’ll be familiar with DAOs as the digital co-ops behind DeFi protocols and other crypto projects. But back at Ethereum’s start, there was basically one DAO, and it was literally called The DAO. It functioned like a giant onchain venture fund.The documentary opens with the hack of that project in 2016. Griff Green, Christoph Jentzsch, and Lefteris Karapetsas narrate those sleepless days as they tried to keep the first Ethereum experiment from falling apart in real time. Their recollections give the film its pulse. 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In a careless moment of vanity, he edited — under a user name associated with him — a Wikipedia page for a Canadian TV show he’d once appeared on and added himself to the list of show’s notable alumni as a “notable mathematician.” That tiny edit was enough to connect the dots between his real identity and the heist. But that wasn’t enough to bring him to justice, as Medjedovic still remains at large. In March 2024, Medjedovic told DL News he was self-exiled on an island somewhere and claimed to have turned a white-hat hacker — someone who hacks lawfully.Medjedovic declined to speak in the documentary, Craig told DL News.Didn’t Avi Eisenberg prove ‘code is law’?Another hacker that gets plenty of screen time is Avi Eisenberg, the Mango Markets exploiter.In October 2022, Eisenberg manipulated Mango Markets, the Solana-based decentralised exchange, by artificially inflating the price of his own collateral token, then borrowing against it to drain roughly $110 million in assets. 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If you don’t know what later happened, you could be forgiven for thinking as the credits roll that Eisenberg lost the “code is law” defence. “We’re beginning to see the end of the ‘code is law’ defence,” Paul Dylan-Ennis, the author of ​​the book “Absolute Essentials of Ethereum”, says in the documentary.“Filming concluded during the build-up to Eisenberg’s trial, and at the time, the overwhelming expectation among those we spoke to was that he would be found guilty,” Craig said.“The crew had originally intended to end the film with a message saying that Eisenberg’s case had tested the ‘“code is law’” defence in court, and it flopped.”And yet this May a judge said prosecutors didn’t prove Eisenberg defrauded Mango Markets in 2022.Although some in the industry cheered that “code is law” appeared to prevail in court, things were more nuanced than that — as they typically are.While the defence did lean on the idea that Eisenberg’s trades were executed within the logic of the protocol’s code, the judge didn’t conclude that this alone justified acquittal.Instead, the judge’s decision to overturn the most serious conviction — on wire fraud — rested on narrower legal grounds specific to that statute.“While a jury did initially find Eisenberg guilty, as we were preparing to release the film it became clear the judge was seriously considering overturning some of the convictions… which ultimately happened,” Craig said.“The precedent it sets for future cases isn’t clear, but it reinforces the central theme of the film: that we’re in uncharted legal territory where traditional systems are struggling to keep up.”
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2025/10/29 07:11