The RFID Journal has an interesting opinion piece by a professor and a researcher at the St. Gallen Auto-ID Lab in Switzerland about using EPC tags to combat counterfeiting of retail goods:

"Today, bar codes identify only the type of product, not the individual item. So if a clever counterfeiter creates a good replica of a Prada handbag or Rolex watch, complete with a bar code, no one could easily determine whether the product is real or fake. And if a third-party anufacturer hired to make jeans for Levi's runs off an extra 10,000 and sells them without the brand owner ever knowing, these goods are impossible to distinguish from legitimate items.

With EPC tags, however, the brand owners could assign a specific serial number to each item they make or is made for them. These unique identification numbers could be stored in a database on the EPCglobal Network, and when the goods are shipped to a retailer, the retailer could scan the tags and look up whether the numbers are among those assigned by the brand owner, indicating the products are legitimate. All parties in the supply chain could also share track-and-trace information to check whether a product entered the supply chain through legitimate means."

The article goes on to point out that EPC tags can be cloned. One way to avoid cloning is to "develop secure authentication mechanisms, such as the challenge-response techniques that are common in today's contactless smart cards."

The article is well worth a read if you are involved in the manufacture or sale of high-ticket or often-countefeited consumer goods.