FREMGANGSMAATE OG ANORDNING FOR AA SIKRE INFORMASJONSINNHOLDET I ET SIKKERHETSSYSTEM

摘要

Data and associated validation information stored in a nonsecure location are verified as to integrity by cryptograph techniques. Verification activates a gambling system to operate in a gambler-responsive mode, and non-verification activates an alarm mode. The system is used in postal metering, electronic mail, electronic funds transfer and other source data processing systems. The validation information is formed by deriving a first value from the data according to a first relationship, and then deriving the validation information from the first value by means of a nonpublic derivation having an inverse function. The validation word is then associated with the data and stored in the nonsecure portion. Verification is accomplished by deriving 430 a first value from the data by the first relationship, and deriving 450 a second value from the validation information by means of the inverse function. The first and second values are operatively related 450 to determine system integrity. All relationships are one way function, in a preferred embodiment. In a preferred embodiment, the first and inverse second relationships are public and the second relationship is secret. IMAGE