Research On Fast Decrption Attribute-Based Encryption With Fine-Grained Revocation

With the rapid development of the Internet,cloud computing has developed rapidly in recent years.However,cloud computing security is a problem of cloud computing that has always plagued cloud computing.The combination of cloud computing and current Internet knowledge content is also a major application of cloud computing,but the sharing of knowledge content has not been well resolved.One of the characteristic of Attribute-Based Encryption is “one-to-many”.It is consistent with application requirements such as cloud computing knowledge content sharing.Correspondence between the Attribute-Based Encryption strategy and the cloud computing access structure makes the combination of the two more perfect.Attribute-based encryption enables fine-grained management of shared knowledge and data with non-interactive features that are accessible offline.Attribute-based encryption has some natural advantages,but has also some problems with efficiency and key revocation.Attribute-based encryption uses a bilinear pair as the basic computation of the scheme construction,and requires a large number of bilinear pair operations to be computed during decryption.The number of bilinear pair is proportional to the number of attributes.In addition,attribute revocation has always been a problem of Attribute-based encryption.If you want to undo an attribute,you need to re-create a new setup of private keys for all users about this attribute and distribute them to the corresponding ones.If a user is to be revoked,the private key of the users associated with all attributes corresponding to this user is regenerated and distributed.In addition,the cloud computing service is a semi-trusted party.The security of ciphertext update on the cloud in the case of attribute change or revocation is also a problem to be solved.In view of the above problems,this paper mainly studies two aspects as follows :1.A fast decryption scheme is proposed.By transforming the access structure into theunion of the smallest set of expressions of the main disjunctive normal form DFN,then constructing a ciphertext for each minimal combination,and using themultiplication to achieve the decryption.The operation of the attribute set of theaccess structure is satisfied,and finally the ciphertext decryption is performed by afixed number of three pairs of operations,and the security is proved by the selectivesecurity model under the assumption of q-parallel BDHE,and then a two-pairoperation is constructed,and its selective security under the assumption of q-BDHEis proved.2.A fast decryption attribute-based encryption scheme that supports fine-grainedattribute revocation is proposed.The user list is revoked by constructing theattribute user list and attributes.When the key is generated,the user ID and the userattributes are bound together,and finally in the secret.When the attribute base ofthe text policy is encrypted,the ciphertext policy and the attribute user list and theattribute revocation list are nested in the ciphertext,When the attribute is revoked,the fine-grained revocation of the attribute can be implemented by updating theattribute revocation list.And under the standard model,the selective security of thescheme is proved based on the assumption of q-parallel BDHE.