Many techniques are available to authenticate a product, that is to verify its legitimacy as compared to copies. The list of technologies applied to this problem is very long and includes many kinds of complex printing with overt or covert information, holograms, embedded materials and chemicals in trace amounts, magnetic additives, etc. All employ a specially manufactured label or tag that is attached permanently to the true product. Verification of the authenticity of the label or tag also verifies the authenticity of the product. The advantages of these techniques are that they provide unique, difficult to copy ways of differentiating real products from counterfeit ones.
Unfortunately, current authentication technologies are not without weaknesses. Usually, if cost is not a consideration, they can be copied to some degree. In addition, since many techniques rely only on visual inspection for verification, human error becomes a significant consideration. Finally, some methods rely on specialized equipment for verification and may be too expensive, cumbersome or slow to be effective in many situations. Currently, standardization is neither possible nor likely.
What is needed in an authentication technology is one that: 1) gives authentication information that can be detected swiftly an clearly in a quantitative manner; 2) is very difficult to copy; 3) can migrate easily to more sophisticated, more difficult to defeat levels of complexity; and 4) is compatible with existing methods of marking or labelling goods.
A technology that partially succeeds in meeting the above criteria is the "magentics" technology. It operates by searching for the presence of ferromagnetic material attached to the product that is to be authenticated. It analyzes the magnetic signature of the ferromagnetic material, focusing on specific and unique magnetic properties. A number of patents have been issued in this area for applications in authentication and other functions. Unfortunately, this approach has a major weakness in that uncontrollable variations can occur in the results of this measurement due to geometrical factors, thus affecting its accuracy and making it potentially unreliable.
A proper authentication system has many uses. It will provide a method of verifying the authenticity of a product in the field. It is useful in establishing a distinction between real and counterfeit products for legal purposes. When coupled to an actuator, it can be used to control document duplication and other information copying related processes such as photocopying, faxing and data transmission. For example, the unauthorized photocopying of a document may be blocked by adding an authentication reader to a photocopier.