Research On Key Updating And Key Storage Scheme Based On Attribute-based Encryption

As an application mode connecting plenty of computing resources and storage resources,cloud storage provides users with storage services,which can effectively reduce the burden of data management in data sharing.Users can encrypt the data to ensure the confidentiality.Since ciphertext is static,key-compromise becomes an important factor affecting data security.For the key management issues of data sharing in cloud storage,a key updating scheme based on attribute-based encryption and a key storage scheme based on key tree are proposed in this paper,respectively,to protect the security of private data and keys.The main research contents are as follows:(1)For the key-compromise problem of data sharing,a key updating scheme based on attribute-based encryption is proposed.On the basis of attribute-based encryption,multi-helper is introduced in key updating scheme,which realized efficient periodic key updating,and enhanced the security defense capability of the system.At the same time,our scheme has realized revocation of the attributes by updating of the helper key and the user's private key,which ensures the fine-grained revocation of the attributes in the system.In addition,the key updating scheme realizes fine-grained user identity tracking by embedding user identity information in the user's private key.(2)For mass key storage in fine-grained encryption,a key storage scheme based on key tree is proposed based on the existing key storage scheme.To ensure the security of the key,the master key and the path information are generated into encryption key through Hash operation in key tree.The key information is stored on single tree node,which realized key distribution and storage.The key is used to encrypt the plaintext data,to ensure the security in data sharing.In addition,the user access control is provided in the scheme through attribute-based encryption.Only users with access rights can obtain the decryption key to decrypt data,thus ensuring the confidentiality of data.Security analysis and performance analysis of the proposed key updating scheme and key storage scheme are performed respectively in this paper.Security analysis shows that the proposed schemes can satisfy the security,and performance analysis shows that the proposed schemes can effectively solve the key-compromise problem in fine-grained encryption in cloud storage,and reduce the storage overhead and computation overhead,which means it has better performance advantages in key management.