Research On Secret Image Outsourcing Sharing Method Based On Homomorphic Encryptio

Secret image sharing is a classical method in the field of image to protect the information of secret image.The traditional secret image sharing schemes generally generate multiple meaningless shares,and ensure that a certain number of shares can recover the original secret image,thus ensuring the security of the information.At present,the traditional scheme of generating and recovering secret led by the leader and keeping the shares by participants are facing many serious challenges: 1)With the development of technology and the improvement of computing power,various attack methods emerge one after another,and secret images are very vulnerable to malicious attacks from the external attackers,resulting in the failure of secret information recovery;2)The existing secret image sharing schemes based on polynomial are usually computed by Lagrange interpolation in the phase of image reconstruction,which is computationally intensive and requires high computational resources;3)The centralized computing process is prone to conspiracy attack.Once the leader conspires with some of the participants,the original image will be restored regardless of the threshold condition.In order to address the above problems,this thesis presents two solutions,which are apply the homomorphic encryption scheme to the image sharing stage before and after,so that the algorithm can safely outsource computing.Two methods of sharing secret image outsourcing with homomorphic encryption technology can protect the important data from tampering and save a lot of computing resources.The decentralized outsourcing computing environment can prevent secret information disclosure.The detailed research results are as follows:(1)In order to address the problem of large amount of computation and high requirement of computing resources for users in the recovery process based on the Lagrange interpolation,this thesis puts forward a calculation method of post-encrypted secret image sharing outsourcing based on blockchain.The method introduces the homomorphic encryption technology based on polynomial secret image sharing scheme,and deploys data storage and management tasks on block chains to ensure that the stored data is not tampered with or destroyed.In the secret image recovery phase,this method outsources the computationally intensive polynomial restoration process to reduce the user’s computing resource requirements.Finally,the data reconstruction task is completed by rebuilding the original image in encrypted form and the result obtained by the user’s decryption.The experimental results demonstrate the security and efficiency of the proposed scheme,and provide a new idea for secret image sharing to be applied in outsourcing environment to restore the original image.(2)To address the vulnerability of secret images and the unprotected share in the centralization process,this thesis presents a cloud server-based outsourcing method for preencrypted secret image sharing.Before the secret image sharing stage,the original image is encrypted with homomorphic encryption,and the encrypted image is uploaded to the outsourced computing center.All operations except encryption and decryption can be securely outsourced.The reconstructed domain file is decrypted by the user using the local key to get the original image.The homomorphic encryption algorithm ensures that computing is outsourced securely and inevitably increases computational complexity.To solve this problem,this method introduces the prefixes-sum strategies,further optimizes the algorithm,improves the resource consumption of complex computing,and ensures the efficiency of outsourcing computing.