> When Bitcoin had built in checksums on addresses [..] There are no address checksums in the Bitcoin blockchain; all contracts/scripts on the blockchain refer

> When Bitcoin had built in checksums on addresses [..] There are no address checksums in the Bitcoin blockchain; all contracts/scripts on the blockchain reference raw hashes. Only at the application level -- e.g. sending an address to a friend in an email -- does Bitcoin make use of checksums, since blockchain space is fairly precious/expensive.