\n
![](\"https:\/\/images.cointelegraph.com\/cdn-cgi\/image\/format=auto,onerror=redirect,quality=90,width=840\/https:\/\/s3.cointelegraph.com\/uploads\/2023-09\/ae4f3320-4e1d-4ffb-a53a-0bbeead11e77.jpg\")
<\/p>\n
\n<\/p>\n
Not a single fraud proof has been submitted on Arbitrum since it first launched its mainnet with the built-in security feature in August 2021, according to Ed Felten, co-founder and chief scientist of the Arbitrum-building Offchain Labs.<\/p>\n
Operating as an Ethereum layer-2<\/a>, Arbitrum\u2019s interactive, multi-round fraud proofs<\/a> work by allowing a layer-1 verifier contract to decide whether the challenger\u2019s fraud-proof submission is valid. If so, the fraudulent validator\u2019s stake is slashed. <\/p>\n Fraud proofs are submitted by challenging validators when it considers another validator to have fraudulently or otherwise incorrectly assembled an incoming batch of transactions into the next block.<\/p>\n However, Arbitrum\u2019s mainnet is yet to see a fraud-proof attempt let alone a successful challenge, Felten told Cointelegraph at Korean Blockchain Week on Sept. 4:<\/p>\n \u201cNot on mainnet. We did have one or two on Ethereum proof-of-work (POW). After the Merge, […] there was a version of Arbitrum running on the Ethereum POW fork and somebody did try to steal all the data and there was a successful challenge which defeated that.\u201d<\/p><\/blockquote>\n Felten said few fraud proof attempts have been made because malicious-intended validators are risk losing their entire stake.<\/p>\n \u201cIf any one person notices it and disputes your claim then you will surely lose your stake, so there\u2019s a stronger disincentive to try,\u201d Felten added.<\/p>\n Both Arbitrum and Optimism operate as optimistic rollups!<\/p>\n However, Optimism and Arbitrum differ in their approaches to fraud-proof mechanisms.<\/p>\n Arbitrum: multi-round \u2192 longer confirmation times, more secure 4\/ pic.twitter.com\/mp0Nj86Fxz<\/a><\/p>\n \u2014 The Smart Ape (@the_smart_ape) September 1, 2023<\/a><\/p><\/blockquote>\n Felten said there\u2019s currently a permission set of validators<\/a> \u2014 roughly 12 \u2014 that participate in the fraud proof game.<\/p>\n He also added that Arbitrum is rolling out a new iteration of the fraud proofs called \u201cBOLD\u201d protocol \u2014 (Bounded Liquidity Delay) which he says gives Arbitrum a faster guarantee for challenges.<\/p>\n \u201cIn the current version […] an adversary who’s willing to sacrifice multiple stakes can arrange to cause \u201cN\u201d weeks of delay if they’re willing to sacrifice \u201cN\u201d stakes […] But the BOLD protocol says no matter how many stakes they sacrifice, they’ll be defeated in about eight days.\u201d<\/p><\/blockquote>\n Related: <\/em><\/strong>Arbitrum founder says Stylus is a game changer for EVMs <\/em><\/strong><\/a><\/p>\n Arbitrum\u2019s BOLD protocol was rolled out by Offchain Labs on Aug. 4.<\/p>\n After months in dev, we\u2019re announcing BOLD (Bounded Liquidity Delay), a new dispute protocol that enables permissionless validation for Arbitrum chains, potentially removing the need for permissioned validation, dramatically improving decentralization. https:\/\/t.co\/SHegVRGqXf<\/a><\/p>\n \u2014 Offchain Labs (@OffchainLabs) August 3, 2023<\/a><\/p><\/blockquote>\n Felten said Arbitrum\u2019s fraud proof feature will soon be permissionless,<\/a> allowing anyone to push towards ensuring the correctness of the chain when challenges are made.<\/p>\n Magazine: <\/em><\/strong>DeFi Dad, Hall of Flame: Ethereum is \u2018woefully undervalued\u2019 but growing more powerful<\/em><\/strong><\/a><\/p>\n<\/div>\n\n
Optimism: single-round \u2192 faster<\/p>\n\n