Abstract: The present invention involves an account transaction authentication system and method which provides user verification of transactions. The method for authenticating an account transaction includes associating an account with a device; creating a confirmation message on the device for a transaction; and authenticating the transaction if a confirmation message is received from the device. The method may use an authenticating device in the form of a personal computer connected to a communications network, a mobile telephone, a wireless personal digital assistant, and may also include a biometric device. Authenticating may involve encryption keys for validation. The computer associates an account with a user account device, and also communicates with the financial institution and to determine that the account transaction requires authentication. The computer activates the user account device to enable the account user to authenticate the account transaction.