Method and apparatus for secure data storage and manipulation using magnetic media

摘要

Data recorded on a magnetic medium may be securely identified and manipulated for use in credit balance applications by determining a magnetic fingerprint benchmark on the medium as well as a distance between this benchmark and any pre-selected magnetic feature such as a magnetic transition of a data bit of the data set. Verification of the data may be achieved by measuring this distance and comparing it with the distance recorded at the time that the data was originally placed on the medium. As there is a detectable difference in accuracy between reading this distance as contrasted with illegitimate attempts to write false data at a pre-selected distance from the benchmark, attempts at forgery are detectable.