Although Customer-to-Customer (C2C) business model has been around for years, second-hand markets of digital contents over the Internet are still unpopular. A key factor to the success of second-hand markets lies in the support of rights management of digital contents redistribution over the Internet. Although various watermarking protocols have been proposed to achieve digital rights protection over the Internet, they do not generally provide protection over a second-hand market. In this paper, we propose a buyer-reseller watermarking protocol that protects the interests of buyers, resellers and the original sellers. The protocol is adapted from a previous work proposed by Memon and Wong [6], which defends the interests of buyers against sellers? unethical distribution of watermarked contents. Our protocol makes use of watermark certificates to distribute the information of buyers? identities. An implementation outline of the proposed protocol is given.