Image watermark embedding and tracing method and system

The invention discloses an image watermark embedding and tracing method and system, and the method comprises the following steps: secret key generation: generating a plurality of pairs of asymmetric secret keys, including a plurality of pairs of public keys and private keys; multiple watermarks are generated, a random number generator is used for generating multiple pieces of watermark information, and each piece of watermark information can be independently embedded into the image; watermark information encryption and signature: encrypting each piece of to-be-embedded watermark information, and encrypting the watermark information by using a public key to obtain an encrypted watermark; performing digital signature on the encrypted watermark by using a private key to obtain a digital signature result; image watermark embedding: embedding the encrypted watermark and the digital signature result into a frequency domain in the image, wherein each image watermark is embedded in a scattered manner; according to th