Patent ID: 8250288

Claim:
A flash memory storage system, comprising: a controller, having a rewritable non-volatile memory; and a flash memory chip, electrically connected to the controller; wherein when the controller writes a security data in the flash memory chip, the controller uses a processing time of writing the security data in the flash memory chip as a data token corresponding to the security data, generates a corresponding message digest according to the security data and the data token by using a one-way hash function, stores the data token in the rewritable non-volatile memory, and stores the corresponding message digest in the flash memory chip, and wherein when the controller reads the security data from the flash memory chip, the controller reads the data token from the rewritable non-volatile memory, generates a comparative message digest according to the read security data and the read data token by using the one-way hash function, reads the corresponding message digest from the flash memory chip, and determines whether the read corresponding message digest matches the comparative message digest, and the controller outputs a warning message if the controller determines that the corresponding message digest does not match the comparative message digest.