Research On JPEG Image Encryption Algorithm Based On Content-association

With the rapid development of mobile Internet and multimedia technology,network bandwidth has been continuously improved,traffic charges have also been continuously reduced,and a large number of multimedia storage requirements have been transferred to the cloud.As the most important information carrier in daily life,more and more users choose to store images in the public cloud.In a public cloud environment with a high degree of exposure,the security of user image content privacy during transmission and storage is one of the important issues that cannot be avoided in the development of public cloud storage.Image encryption is the main solution to information leakage,and JPEG is one of the most popular digital image formats in the current network,so research on JPEG digital image encryption technology is a crucial topic.Through theoretical analysis and research on traditional data encryption technology and existing commonly used digital image encryption models,the shortcomings of encryption schemes such as low key correlation,key attributes of unencrypted images,increased ciphertext file size,and large time overhead have been summarized,Does not meet the current large-scale application in the public cloud environment.A JPEG digital image encryption algorithm based on content association is proposed,which effectively solves the above various defects.According to the special data structure of the JPEG image format,the file data is divided into key content parts such as metadata attributes,primary decoding token and secondary decoding token,and compressed data part based on the JPEG data stream.In order to reduce the redundancy of the key file,a key unit format including byte offset and bit offset is designed.The algorithm encryption process is divided into two parts,one is to analyze and locate the key data to form a key unit sequence,and the other is to randomly associate the compressed data to form a key unit sequence.Finally,several unit sequences are combined into a key file,and the source file data stream forms ciphertext after backfilling with irrelevant data.In order to verify the various superior characteristics of the JPEG digital image encryption algorithm based on content association,detailed theoretical analysis and experimental tests are performed for each performance of the algorithm.Experimental and test results show that the content association-based JPEG digital image encryption algorithm has good characteristics in terms of encryption effect,security,file size consistency,and time overhead.