Patent US 10,423,960

Methods of and systems for securely monitoring a balance of a payment account include storing, in a first database, ledger data and storing, in a second database, wallet data. Wallet data includes a wallet balance value for the payment account. When a transaction is initiated using the payment account, an access operation is performed on the wallet table. Illicit or improper modifications can be detected by deriving a ledger comparison value from the ledger data and comparing the derived ledger comparison value to a wallet comparison value from the wallet data.