In some ways it was! Blockchain is (in essence) a signed ledger of double-sided transactions (that happens do be duplicated for error/fraud checking). The first

In some ways it was! Blockchain is (in essence) a signed ledger of double-sided transactions (that happens do be duplicated for error/fraud checking). The first part of that (ledger of double-sided transactions) has been around since the 13th century, and been replicated is almost all accounting software.