The invention discloses a
blockchain-assisted
privacy protection image retrieval method, which comprises the following steps: firstly, an image owner extracts image features by using a CNN model, then encrypts an image and the features by using an SM4
algorithm and a secure kNN
algorithm, and uploads a
ciphertext image to a
cloud server; then, the image owner calculates the hash of the
ciphertext image and generates a Merkle
hash tree, then an index table of
encryption features is constructed by using an LSH
algorithm, and the index table and the
Merkle tree are uploaded to an alliance chain; and finally, the user uploads the
encryption feature of the query image to the alliance chain, retrieves the IDs of the first k images similar to the image, and returns the k IDs to the cloud, the cloud sends the corresponding image to the user, and the user decrypts the image to obtain a
plaintext image. The advanced block chain technology and the
cryptography technology are adopted, the accuracy of the
retrieval result can be guaranteed, and the integrity of the image data stored in the cloud can be verified; meanwhile, the
image retrieval problem in the multi-cloud environment is solved, and the efficiency of the retrieval scheme is improved.