TMIB: A Traceable Multi-user Image Retrieval Scheme based on Blockchain

With the development of cloud computing technol-ogy, more and more users choose to encrypt their huge image data and store them on the cloud server to save their limited storage resources. In order to conduct a safe and effective query operation, it is necessary to research the technology of searching encrypted images. However, most of existing research schemes on encrypted image retrieval technology are focused on the improvement of efficiency and accuracy, ignoring the threat brought by malicious cloud servers or malicious nodes. To solve this problem, we propose a Traceable Multi-user Image retrieval scheme based on Blockchain (TMIB). TMIB scheme utilizes the blockchain based on characteristics such as de-centralization and data tamper-proofing to prohibit returning wrong query results by a malicious cloud server. Moreover, TMIB scheme adopts a proxy re-encryption approach to achieve availability in multi-user scenarios. Furthermore, a watermark is embedded in the encrypted images to track the malicious users for preventing malicious users from distributing the images again. Finally, we analyze the security and feasibility, proving the high precision and efficiency of TMIB scheme in the actual scene through experiments.