Outsourcing a company’s data storage and management system increases data security risk and generates a mistrust among adopters, that their data will remain secure and undisclosed. Due to limitations of the SLAs in this direction, the challenge is to build mechanisms that provides data security by design and assures data nondisclosure protection implicitly. In this paper we present an evaluation of the Data Confidentiality in Cloud Storage using a brute-force setup with the aim of studying its effectiveness. Through experimentation on the CloudSim environment we found that the probability of unauthorized data reconstruction can be exponentially decreased by using a sufficiently large number of chunks. Also, increasing the number of used storage volumes leads to a linear decrease of unauthorized data reconstruction.