Co-Check: Collaborative Outsourced Data Auditing in Multicloud Environment

Table 1

Evaluation results of our approach.

Size (bits)	Blocks ()	Sectors ()	Challenge blocks (#)	(s)	(us)	(ms)	(ms)
80	64	64	32	24.223	20	3121	1063
80	32	128	16	23.326	15	154	1223
80	16	256	8	25.352	18	81	1414
320	128	128	64	84.337	29	927	1671
320	64	256	32	81.216	19	512	2085
320	32	512	16	84.164	16	305	2847
1280	256	256	128	330	44	4950	3289
1280	128	512	64	336	119	9110	6761

is the time cost for preprocessing; is the time cost for generating challenge; is the time cost for generating proof; is the time cost for verification.