A system, method, and article of manufacture are provided for identifying electronically distributed software after distribution. First, software is electronically transferred to a user over a network in exchange for payment during a transaction. After the transaction, a proof-of-purchase is then downloaded...http://www.google.com.tw/patents/US20030126033?utm_source=gb-gplus-share專利 US20030126033 - System, method and article of manufacture for software source authentication for return purposes
