An anti-counterfeit authentication system provides authentication services over available communication networks. The system assigns unique anti-counterfeit certificates to authentic items. The certificates are stored in anti-counterfeit tags that are attached to the authentic items. An authentication server provides authentication services to authentication clients over the communication networks. The authentication clients read, via tag readers, the anti-counterfeit certificates from the tags associated with items to be authenticated, provide the anti-counterfeit certificates to the authentication server which determines authenticity and supplies authentication results back to the authentication clients.