The second-hand economy is booming—but trust is still its weakest link. Buyers often hesitate due to concerns about counterfeits, stolen goods, or unverified product condition. What if every pre-owned item came with an unbreakable chain of authenticity? Imagine a world where resale platforms could verify the originality of goods with traceable ownership history, like a digital passport.   How should a second-hand marketplace that builds trust between sellers, buyers, and platforms be made user-friendly? What kind of technologies and processes could be utilized to enable tracking on a good enough level?   This project revolves around the culture that cherishes recycling and explores the opportunities to make it a true option for even further audiences. As the end results, demos of user interfaces and working logics for such system are expected to come out.