Verifiable deletion method supporting outsourcing data fine-grained insertion in cloud storage

The invention belongs to the technical field of cloud storage, and discloses a verifiable deletion method supporting outsourcing data fine-grained insertion in cloud storage, which comprises the following steps: step 1, initialization: generating related key pairs and public parameters; step 2, data outsourcing: outsourcing a large-scale file F to a cloud server by a user; step 3, data insertion: inserting a new data block into the outsourcing file, and checking a data insertion result; and step 4, data deletion: enabling the user permanently to delete outsourcing data blocks which are not needed any more, retains useful data blocks in the cloud server, and verify a deletion result. According to the method, a new scheme is designed by using a number rank-based Merkle hash tree (NR-MHT), and the scheme can simultaneously realize block-based outsourcing data verifiable deletion and fine-grained insertion under the condition of not depending on a trusted third party (TTP). Meanwhile, through detailed safety anal