An Efficient Provable Data Possession Scheme with Data Dynamics

Ateniese et al proposed an efficient Provable Data Possession scheme which uses only hash and symmetric-key cryptographic functions, but it cannot support block insertion. To achieve full data dynamics, a SN-BN table which maps the logical indices of blocks to their physical ones is introduced. The SN (Serial Number) is used to determine which blocks are included in tags, while the corresponding BN (Block Number) is used to retrieve the actual data blocks. Therefore, the remaining tags need not to be recomputed with new blocks while a block is inserted. Therefore, it can support full data dynamics including block modification, deletion, insertion and appending. Because of its high efficiency and full dynamics, our scheme is very suitable for applications in which some resource-constrained clients are used to check the data possession and the data needs to be updated after being outsourced.