Wireless Security.pdf - PDF Archive

RFID Security 627
The data carried in a tag can be in most formats, as long as both the tag and the reader
agree on it. Many formats are proprietary, but standards are emerging. In the next section,
we look at the Electronic Product Code (EPC). The EPC is considered the RFID
replacement for the Universal Product Code (UPC) barcode and, as such, will have a
huge impact on retail sales in the future.
The UPC bar code has been the accepted means of conveying pricing at the POS in
retail stores since the 1970s (see Figure 24.5 ).This particular UPC is from Syngress
Publishing’s WarDriving : Drive , Detect , Defend . Each UPC bar code contains basic
information about the bar coding system, the manufacturer, the item, and a check digit.
Because 5 digits are used for both the manufacturer and the item, the total number of
manufacturers is limited to 100,000, each limited to 100,000 items. While this allows for
10,000,000,000 products, it is more restrictive than is obvious. As manufacturers add new
items and close out old product lines, UPC numbers are quickly being used up. The UPC
does not allow serial numbers to be encoded into the bar code.
24.6.1.1 Electronic Product Code
The new Electronic Product Code uses the EPCglobal organization’s General Identifier
(GID-96) format. GID-96 has 96 bits (12 bytes) of data. Under the GID-96 standard,
every EPC consists of three separate fields: the 28-bit General Manager Number that
identifies the company or organization; the 24-bit Object Class that breaks down products
into groups; and the 36-bit serial number that is unique to the individual object. A fourth
field consisting of an 8-bit header is used to guarantee the uniqueness of the EPC
Figure 24.5 : Typical UPC bar code
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