Privacy-preserving Parallel Cipher Algriothm In Cloud Computing Environment

Security is an important part of the cloud computing network. In large data storage and security protection on the cloud, adding privacy protection mechanisms is one of the commonly used means. However, due to the characteristics of large amount of data, the encryption of data in the cloud demonds the high spatial and temporal requirements. Taking advantage of parallelism in a cloud environment to encrypt the data is very meaningful to improve the speed of encryption.In recent years, researches in cloud computing security field have made some achievements. Privacy protection in cloud computing security researches mainly focus on access control based on the identity or attributes to improve security, while metadata need to be encrypted to prevent the leak of sensitive information. The parallel distributed ciphertext computing can effectively enhance the security of the data and the distributed storage can prevent a single point break which may cause the complete disclosure of sensitive information. Parallelization of the serial encryption algorithm can speed up the encryption of sensitive information in a cloud environment, combined with the hybrid cloud mechanism to provide efficient secure cloud storage.This thesis analyzes the method of parallel distributed computing Hill cipher encryption algorithm and using the Hadoop MapReduce framework to achieve a cloud environment for sensitive information encryption and decryption process. And the parallel hybrid chaotic encryption algorithm is proposed, through a combination of different chaotic systems to improve the security of encryption, combined with the characteristics of the cloud environment parallel to achieve a plaintext block encryption. Theory and Practice shows that the encryption speed can be increased in hadoop MapReduce cloud environment. The symmetric encryption algorithm, including encryption algorithm based on Hill’s chaotic system and based on hybrid chaotic encryption algorithms are able to achieve a distributed storage and parallel encryption to improve the speed of encryption in a clustered environment.