Patent ID: 7761347

Claim:
An RF-ID (Radio Frequency Identification) tag management method for authenticating an RF-ID tag attached to merchandise, comprising: reading tag data from the RF-ID tag by a first ID-reader, and reporting the tag data to a system operation server with a first process ID assigned to the first ID-reader; registering the first process ID as being related to an identification number of the tag data in a log database on the system operation server; searching the log database for a second process ID which is the most recently recorded process ID as being related to the identification number; and detecting a counterfeit RF-ID tag by determining whether a transition from a second process indicated by the second process ID to a first process indicated by the first process ID is possible as compared with process transition rules which are used to determine whether transitions between processes performed in an overall business system are possible or not, wherein each of the first process and the second process indicates one of the processes in the overall business system, and wherein process IDs, including the first process ID and the second process ID, are numbers indicating which of the processes in the overall business system have been performed on the merchandise.