B-Spot: Blockchain and Steganography based Robust and Secure Photo Transmission Mechanism

In this paper, a Steganography and Blockchain based robust and secure photo transmission mechanism, named B-Spot, is proposed. At the sender side, firstly, a 3-3-2 LSB image steganography algorithm is used to hide a secret photo into a cover photo. Therefore, the existence of the secret photo is concealed. Then the stego-image is broken down into pixels and embedded into blocks. Blocks are connected by the hash values forming a blockchain. Any modifications on the blocks are reflected by the breakage of the chain, which makes the mechanism tamper-evident. Another copy of the blockchain is stored in a hash table for the latter recovery process. The blockchain and the hash table can be transmitted via any network. When the receiver receives the data, it firstly executes the verification process to check integrity of the blockchain. Then the lost and tampered blocks are recovered by referring to the hash table, which makes the mechanism more robust to noises. Finally, the stego-image is reconstructed from the recovered blockchain. Then the receiver can obtain the secret photo following the extraction algorithm. The simulation results show that the proposed mechanism has high data capacity, better imperceptibility, reasonable computing time, and strong robustness to noise. This mechanism adds an extra layer of security and robustness to the existing schemes.