Non-Repudiable Dynamic PDP with Stronger Security based on Stateful Rank Based Skip List

Abstract

To guarantee the integrity of data stored in cloud servers, a number of techniques have been proposed. For security analysis, we generally assume honest but curious servers and honest clients. However, for dynamic data, we need to assume stronger adversaries since a malicious server or a malicious client can deny the update of stored data. Until now, some schemes have been proposed to give the security against the stronger adversaries. However, almost schemes are safe for adversarial<br/>clients or malicious servers, but not both. So, in this paper, we propose a PDP scheme supporting dynamic data and guarantees the integrity of stored data against malicious servers and clients. To design the scheme, we firstly design a new authenticated data structure so-called Stateful Rank based Skip List which reflects the latest version of stored data. Based on the data structure, we design a non-repudiable dynamic PDP which permits servers and clients to manage the version of stored data in an authenticated and non-repudiable way, so that our scheme prevents malicious servers and clients from cheating the latest version of the stored data.