Abstract: Provided is a product on which is imprinted an encrypted message obtained by encrypting a message sent along with the product from a sender to a recipient, a method for manufacturing the product, and a system for manufacturing the product. The product manufacturing system has a general web server, an encryption calculating apparatus, an issued encryption values database, a specialized web server, an archive database, and an imprinting apparatus. The product manufacturing system is provided with a message acquiring section that acquires the original message sent along with the product from the sender to the recipient, an encryption calculating apparatus that generates a calculated encryption value by using a hash function to compress a calculation target message extracted from the original message, and an imprinting control section that controls imprinting of the calculated encryption value onto the product.