How we built a tamper-evident accounting ledger for retail SMBs using SHA-256 hash chaining

At Momentum (a product by ltiora) ( https://ltiora.com/ ), we build retail and wholesale ERP software. One of the more interesting engineering problems we tackled was making our accounting ledger tamper-evident, meaning retroactive modification of historical financial records is cryptographically detectable. The Problem Most accounting software for SMBs treats historical records as editable data. An administrator with sufficient access can modify a past journal entry, and while most platforms lo