Data sharing benefits various aspects of people’s daily lives, while in most existing centralized sharing paradigms, data generators do not have the ownership or control over their data. There have been many recent works on decentralized data sharing that provide the data owners with full control over their generated data in a decentralized setting. However, besides guaranteeing the owners with more control over their data, record tracking for data requesters becomes challenging due to the decentralization attribute. To address this issue, we propose SecLog, an atomic-swap based secure logging for decentralized data sharing. We utilized the idea of atomic swap from existing works, modifying the triggered event when the access to the queried results is given to the data requester, a record will be automatically included on the blockchain. Simulation results indicate that our proposed protocol costs less gas compared to the original payment-based atomic swaps and our source code is available at: https://github.com/avocado-avery/SecLog .