FWAAAA
A toolkit for executing 51% attacks
About
The problem it solves This is a swiss-army knife for 51% attacks. Great for stress-testing your PoW test net. Great for ambushing rogue PoW forks that didn't get the memo on ecological sustainability (cough ETHW) Features - Censor particular txns. - Shadow mine a longest-chain, then release your fork to the network. - Initiate double spend attacks against exchanges & bridges. Analytics - Geographically visualize nodes in the network - See which fork the miners think is the chain. Entertaining Experiences - NFT drops that get "wiped away" - 51% attack games - Educating users on risks of attacks
How it's made
Challenges we ran into The hardest part was setting up the 51% attack. -- Finding enough HASH power wasn't difficult. I operate very large GPU clusters, and I chose the ETC Mordor PoW Testnet as my target. I had 1000x its hash rate. It certainly crazy looking through the go-ethereum (geth) code base, without having ever used the GO computer language before! I was able to identify where txns & reorgs were processed, and inserted an API for controlling the logic that manipulates/censors txns in a block. But the worst was the dependency hell -- trying to figure out which combination&version of out-dated clients worked for my hardware. While compiling the etherem-classic fork of geth. I spent an entire day trying to match the correct versions between go, the github repo, and their dependencies. Also challenging was that ethminer didn't support the latest CUDA version of my GPU cluster. The solution was to setup a startum mining pool and test the many mining-pool clients, (e.g. gminer, lolminer, trex). Some client combinatinos failed without useful error messages. Some only produced stale blocks. Finally Trex seemed to understand