A survey on multi-cloud storage security: threats and countermeasures

Abstract

In this paper, we study multi-cloud storage technologies that share information as a single system using services from different cloud providers. These technologies provide advantages related to the availability and cost but need protections from security threats such as collusion and data leakage, limiting its massive adoption. We analyze security methods for multi-cloud storage and present the last advances in the field. We show that security systems based on homomorphic encryption are more promising than conventional security methods due to the possibility of performing operations over encrypted data.