Abstract: As the Internet plays a more and more important role in economic society and national security,the security of network data transmission has attracted the attention of academic circles in recent years.One of the hot research issues is the encryption and transmission of digital image information.The traditional way of image encryption is relatively simple,has some flaws and is easy to be cracked.For this question,the content of the research is a composite encryption algorithm based on involutory matrix,matrix decomposition and information hiding.The original image is encrypted by using the matching matrix,and the encrypted image is decomposed into several low-pixel images and then hidden into the public information.The example shows that this method has high safety performance and good effect.

Key words: Image encryption, Information hiding, Involutory matrix, Matrix decomposition