A analysis paper printed by The Hebrew College in Israel stories having found the “first proof of a consensus-level assault on a serious cryptocurrency.” The paper is at the moment awaiting peer evaluate 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 assist 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
Uncle Maker
Ethereum is maintained via a proof-of-work consensus mechanism, which will likely be moved to proof-of-stake this September. Nonetheless, thus far, the community seems to be vulnerable to the assault recognized in by The Hebrew College.
The consensus-level assault is known as an Uncle Maker assault inside the paper in reference to the “uncle” blocks used within the exploit. Blocks inside the Ethereum blockchain act as a set of data which are checked, distributed, and verified throughout all the community. Uncle blocks are legitimate blocks which were faraway from the primary chain however nonetheless obtain rewards.
“The assault permits an attacker to switch opponents’ 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 inside the block, which will likely be demoted from the main-chain.”
Miners can set a block’s timestamp inside “a sure cheap 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 consequence. F2Pool is among 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.
We’re at the moment trying to provide concrete estimations for each of your questions utilizing real-world knowledge, which will likely be printed instantly when we’ve them!”
The Hebrew College has “concrete fixes for Ethereum’s protocol” and created a patch for consideration. Yaish acknowledged in a weblog submit that the data was “responsibly disclosed to the Ethereum Basis” earlier than publication.
