Address Poisoning Checker

Address poisoning works because wallets abbreviate: someone checks the first four and last four characters, sees a match, and pastes the wrong one. So this compares exactly those ends rather than overall similarity, which would flag unrelated addresses constantly. Two addresses matching at both ends is not coincidence — producing one takes deliberate effort — and that case is separated from single-end matches, which happen by chance often enough to be unremarkable. Compares the first and last four characters, because that is what wallets abbreviate and what people actually check. Matching at both ends is deliberate effort rather than coincidence; matching at one end happens by chance often enough to be unremarkable. The defence is never to copy from your own history.