This issue lists the bugged we fixed in the source code of contracts but that are present in already deployed contracts. - The ECDSA library returns `0x0...` instead of reverting for invalid signatures: https://github.com/trustlines-network/project/issues/829. Present in every equivocation inspector (deposit / validator slasher) deployed before https://github.com/trustlines-protocol/blockchain/commit/54fc47d74590660fe9e5aca0f3c4bbfd52618408.