Blockchains are unique in that, when a transaction has long been recorded and confirmed, it may?�t be changed. The ledger only permits 1-way facts modification.Щоб по?а?и ?о?г?вл?, ко?и???ва?ам по???бно за?е?????ва?и ака?н?, п?ой?и ве?и??ка??? о?оби, к?пи?и/депон?ва?и к?ип?овал???.