Cost comparison among provable data possession schemes

Abstract

Provable data possession (PDP) provides mechanisms to eciently audit the integrity of data held by third parties, like cloud service providers. While multiple PDP schemes have been proposed, there is no research to date that provides in-depth cost analysis for PDP. This research fills that gap by (1) collecting and analyzing cost data for four PDP schemes, (2) providing generic cost models (math-ematical formulae expressing abstract models which can be used to infer future cost), and (3) comparing overall cost eciency of each PDP scheme. For the schemes considered in this study, we find all have nearly identical costs in practice; however, sophisticated schemes designed with low communication complexity have higher preprocessing or storage costs which, depending on audit param-eters, impact total scheme cost. We conclude that MAC-PDP and CPOR schemes are similar, whereas the cost of A-PDP becomes relatively expensive at large file sizes. Our basis cost projections show tagging, storing and auditing a file for one year at one audit per hour is at least $160 for a 1 GB file, $170 for a 1 TB file, and $2,000 for a 1 PB file using a cost model based on the Amazon S3 service.