hard20 pts · first answer countscryptographysmart-contract-security

Domain separator after a chain split

A token computes its EIP-712 DOMAIN_SEPARATOR once in the constructor and stores it as immutable. What is the risk if the chain later splits into two chains with different chain IDs?

A.Nothing; the chain ID can never changeB.All signatures become invalid on both chainsC.The token stops being ERC-20 compliantD.Both chains keep the old separator, so a permit signed on one chain can be replayed on the other; recompute when block.chainid differs from the cached value

← Using a signature as a nonce Hash collision with encodePacked →