Research on modifiable digital watermarking scheme based on QRcode and blockchain

Existing digital watermarking techniques for vector geographic data based on spatio-temporal domains face problems such as high computational complexity, low embedding capacity of effective watermark information, and low security of watermark storage. To cope with these challenges, a digital watermarking scheme based on quick response code (QR code) and blockchain is proposed. In this scheme, the QR code is used as a carrier for the real watermark information, which increases the payload of the watermark. The authentic watermark is stored using blockchain and proprietary file system (IPFS) technology, and the hash index value returned by the blockchain is embedded into the vector map after folding, which alleviates the security problem of centralized storage to a certain extent. When a watermark verification or modification event occurs, the blockchain records user identity and timestamp information. Experimental results show that the scheme is robust to attacks such as data cropping, compression and geometric transformation, and can effectively extract correct watermark data.