Although modern information technology provides real-time and visual management convenience for commodity supply chains， digital information circulation brings privacy security issues. To address this problem， an ownership transfer and tracking scheme is proposed through using RFID， blockchain and modern cryptography technology. Specifically， we first establish a formal model of the ownership transfer and tracking scheme. Then， we define the security of the ownership transfer and tracking scheme from two aspects： unforgeability and privacy. Finally， we design ordered aggregate signature based on which an efficient， secure and privacy-protected ownership transfer and tracking scheme （OTT） is presented. The tags of OTT are only required to have basic computing and storage capabilities， so the OTT scheme can be applied to lightweight tags. The ordered aggregate signature not only compresses the data of blockchain but also provides a way to characterize the circulation path.