A research paper revealed by The Hebrew College in Israel stories having found the “first proof of a consensus-level assault on a significant cryptocurrency.” The paper is at present awaiting peer assessment however makes use of publicly out there on-chain knowledge and Ethereum’s open supply codebase to affirm its conclusions.
At its core, the paper highlights a difficulty the place miners can change the timestamp associated to a mined block to keep away from elevated issue on the community. On-chain knowledge seems to help the declare as Aviv Yaish, one of many paper’s authors, highlighted F2Pool’s block timestamps being artificially altered to enhance rewards.
(9/12) Every time F2Pool’s block timestamps attain the purpose the place mining issue is meant to lower, they artificially set them to be one second earlier. F2Pool has been executing this assault over the previous two years, and the proof has been hiding in plain sight! … pic.twitter.com/mDEG2UqXZh
— Aviv Yaish (@yaish_aviv) August 5, 2022
Ethereum is maintained by means of a proof-of-work consensus mechanism, which shall be moved to proof-of-stake this September. Nevertheless, so far, the community seems to be inclined to the assault recognized in by The Hebrew College.
The consensus-level assault is known as an Uncle Maker assault throughout the paper in reference to the “uncle” blocks used within the exploit. Blocks throughout the Ethereum blockchain act as a set of information which are checked, distributed, and verified throughout the whole community. Uncle blocks are legitimate blocks which have been faraway from the principle chain however nonetheless obtain rewards.
“The assault permits an attacker to exchange rivals’ main-chain blocks after the very fact with a block of its personal, thus inflicting the changed block’s miner to lose all transactions charges for the transactions contained throughout the block, which shall be demoted from the main-chain.”
Miners can set a block’s timestamp inside “a sure affordable sure,” usually inside a couple of seconds. One mining pool that was singled out within the analysis was F2Pool, which “prior to now two years, F2Pool didn’t have even a single block with a timestamp” that matched the anticipated final result. F2Pool is likely one of the largest Ethereum swimming pools working with a hashrate of 129 TH/s and producing roughly 1.5K ETH in each day rewards.
The paper additionally highlighted that F2Pool’s “founder has made a comparatively nicely publicized condemnation of competing mining swimming pools, blaming them for attacking his personal mining pool” whereas, in actuality, “F2Pool are attacking different mining swimming pools.”
The financial influence of the assault has not but been formally recognized, however CryptoSlate reached out Yaish who instructed us,
“For every profitable occasion of the assault, F2Pool earned 14% extra from block rewards, and as well as earned all of the transaction charges contained inside.
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The Hebrew College has “concrete fixes for Ethereum’s protocol” and created a patch for consideration. Yaish said in a blog post that the data was “responsibly disclosed to the Ethereum Basis” earlier than publication.