Scheme On Attribute-Based Encryption In Cloud Computing

In order to ensure that the data stored in the cloud service will not be stolen,the main solution is to upload the data in the form of ciphertext to the cloud server.However the traditional public key encryption needs to specify the visitor when encrypting,which can not be applied to the cloud environment for multi-user access to the situation.The attribute-based encryption mechanism,combining cryptography and access control features,enforces that only one persion whose attributes meet the encrypted file access rules can decrypt the file.This method can meet the security needs of the untrusted cloud environment and fine-grained access control.At present,there are many researches about attribute-based encryption.Most of these literatures only support the monotonic access structure.The application in the real scene is limited,and the expression of the scheme is not rich enough.In addition,the security of most existing attribute-based encryption schemes are proved its security in the selective-model,the proof of this method will decrease rapidly as the number of attributes and classification decrease.In the existing attribute-based encryption access control model,the data owner encrypted data with the specified attribute.The distribution of attributes and keys are implemented by the data owner.which increased the total number of keys,storage and huge computational burden,and the data owner need to have always online to distribute keys and attributes for users,the efficiency of attribute revocation is low.In order to solve the above-mentioned problems,the work we have done in this paper is listed as follows:1.Fully Secure Ciphertext-Policy Attribute-based Encryption with Non-monotonic Access Structures.To improve the expressibility and security,a new attribute-based encryption scheme based on ciphertext strategy is proposed,which does not limit the size of attribute space and the number of times of attribute use,and the number of common parameters is constant,which reduces the encryption and decryption efficiency to a certain extent.We also support non-monotonic access structure,so the program is more expressive,the data owner of the control of the file increased.In addition,we use dual-system encryption method in an adaptive model proves that our proposed scheme is completely secure,indicating that our scheme is more secure.In addition,we compared our schemes with existing schemes and tested and validated them.2.A new fine-grained access control model is proposed.Because of the low efficiency of public key encryption,we use the hybrid encryption mechanism,which can get advantages of both symmetrical encryption and attribute-based encryption.In addition,in our mechanism,we introduced a key generation center to distribute attributes and keys for users,reducing the total number of keys and reducing significant storage and overhead.Moreover,we introduced a revoked list to achieve attribute revocation efficiently.We have a detailed description of each module,and gives some of the module pseudo-code.Finally,we compare our scheme with the existing scheme.