Abstract text

An anti-counterfeiting method assigns a product code to a product, and reproduces the product code on the product. The reproduced product code has at least an overt code and a covert code. At normal conditions, the overt code is visible but the covert code is concealed from viewing by a concealment means such as a scratch-off material. A consumer is allowed to conditionally remove the concealment means to reveal the covert code, and send the overt code and the revealed covert code to a verification center to verify the authenticity of the product. At least the complete product code is large enough to identify the product, while the covert code is just large enough to discourage counterfeiting yet at the same time small enough to make it easy for the consumer to uncover.