For the reason that the robustness and tamper detection for existing contentbased watermarking algorithms are poor

an image hash watermarking algorithm is proposed based on compressive sensing. It conducts random projection on image using compressive sensing

and gets compressive measurements which represent the content features of image. By the HMAC algorithm

the image digest is generated and embedded into the original image as watermark. When authentication

the watermark is extracted from the tampered image

and random projection on the tampered image is conducted. By comparing the image digests between original and tampered images

the image authentication and tamper detection are implemented. Experimental results show that the proposed algorithm not only has strong robustness and security

but also has good ability of tamper detection.