Data Slice and Backup Strategy of Cloud Storage Based on ID Signature

This paper puts forward a cloud storage data backup strategy based on ID signature. By using the correspondence relationship between file block ID and its available storage node ID,and the randomly assigned effective storage node to find storage nodes,the strategy improved the efficiency of a primary server.Besides, creating a copy of backup data file at a specified number of fragments and storing data in the optimal backup area in multiple clouds node can not only reduce the cost but also improve its data reliability and availability.