  Copyright detection is an effective method to prevent piracy. However,
untrustworthy detection parties may lead to falsified detection results. Due to
its credibility and tamper resistance, blockchain has been applied to copyright
protection. Previous works mainly utilized blockchain for reliable copyright
information storage or copyrighted digital media trading. As far as we know,
the problem of credible copyright detection has not been addressed. In this
paper, we propose a credible copyright detection architecture based on the
blockchain, called DCDChain. In this architecture, the detection agency first
detects copyrights off the chain, then uploads the detection records to the
blockchain. Since data on the blockchain are publicly accessible, media
providers can verify the correctness of the copyright detection, and appeal to
a smart contract if there is any dissent. The smart contract then arbitrates
the disputes by verifying the correctness of detection on the chain. The
detect-verify-and-arbitrate mechanism guarantees the credibility of copyright
detection. Security analysis and experimental simulations show that the digital
copyright detection architecture is credible, secure and efficient. The
proposed credible copyright detection scheme is highly important for copyright
protection. The future work is to improve the scheme by designing more
effective locality sensitive hash algorithms for various digital media.
