Dynamic Outsourced Proofs of Retrievability Enabling Auditing Migration for Remote Storage Security

Algorithm 3

Algorithm for CSS to perform the batch updates.

Batch_Updates . Input parameters are a batch of update operations, is

the bv23Tree, and are the whole outsourced original blocks. This algorithm outputs an ordered

leaves set , the proof table , and the updated root hash value from the final state bv23Tree .

(1)extract from the largest ordered targeted indices set , by removing the duplicate indices;

(2)read leaves set from ;

(3)obtain ← Proof_Table;

(4)update the file blocks set according to the sequential executions of all update operations ;

(5)perform each of the update operations in sequence on and then obtain the final state ; more specifically,

transform in terms of each operation, and update the status , rank , and hash value of the affected tree nodes

during each transformation; (for the modification operation without transformation, only need to update the

hash values of the nodes on the path from the targeted leaf to the root)

(6)return , where is the authentication hash value of the root of final state ;