Doppler Doppler 2778 13645 33 37402 39 241577 23748 20 37262
58272 53149 129 38535 290 412331
221725 814163 8714
Crosshair Crosshair

A Six-Year-Old Solc Riddle

Can we verify a piece of Ethereum antiquity by messing with the compiler?

Last October we got a request like no other, to verify the oldest NFT ever deployed on Ethereum. It was compiled using Solidity 0.1.5. That's more than 6 years old! By reverse-engineering the bytecode, and understanding the nondeterminism of the compiler (which is complex, but has to do with the memory allocator compiled into asm.js) we were able to reproduce the NFT's bytecode from source. The result allowed us to verify the contract on Etherscan and make our client happy.

Read more