Structural cloud audits that protect private information

Abstract

As organizations and individuals have begun to rely more and more heavily on cloud-service providers for critical tasks, cloud-service reliability has become a top priority. It is natural for cloud-service providers to use redundancy to achieve reliability. For example, a provider may replicate critical state in two data centers. If the two data centers use the same power supply, however, then a power outage will cause them to fail simultaneously; replication per se does not, therefore, enable the cloud-service provider to make strong reliability guarantees to its users. Zhai et al.[28] present a system, which they refer to as a structural-reliability auditor (SRA), that uncovers common dependencies in seemingly disjoint cloudinfrastructural components (such as the power supply in the example above) and quantifies the risks that they pose. In this paper, we focus on the need for structural-reliability auditing to be done in a privacy-preserving manner. We present a privacy-preserving structural-reliability auditor (P-SRA), discuss its privacy properties, and evaluate a prototype implementation built on the Sharemind SecreC platform [6]. P-SRA is an interesting application of secure multi-party computation (SMPC), which has not often been used for graph problems. It can achieve acceptable running times even on large cloud structures by using a novel data-partitioning technique that may be useful in other applications of SMPC.

Efficient Certification and Zero-Knowledge Proofs of Knowledge on Infrastructure Topology Graphs

“…Zhai et al [38] proposed a structural reliability auditor, which discovers dependencies between cloud components. This was later extended by Xiao et al [37] to achieve this privately in secure multi-party computation (SMPC). Their work argues over the dependency graph of cloud components, a data structure which can be directly implemented in the graph signature scheme presented here.…”

“…Consequently, cloud security assurance sought to establish structural properties of virtual infrastructures for isolation and deployment patterns [4,3] as well as for hidden dependency graphs [38,37]. Our own work with an infrastructure cloud and auditing system provider similarly indicates that structural security properties and a projection of trust from an auditing system to a provider are deemed important.…”

Security Risk Quantification Mechanism for Infrastructure as a Service Cloud Computing Platforms

“…They demonstrated the practicality of their system by implementing it, which also showed the lack of privacy measures for the data that is being used. Xiao et al [19] fixed the issue by adding a privacy aspect to the SRA system. They re-engineered the 3-step process of Ref.…”

Towards a Vulnerability Tree Security Evaluation of OpenStack’s Logical Architecture

“…They demonstrated the practicality of their system by implementing it, which also showed the lack of privacy measures for the data that is being used. Xiao et al [13] fixed the issue by adding a privacy aspect to the SRA system. They re-engineered the 3-step process of [12]'work by adding privacy to each step and using Secure Multi-Party Computation (SMPC).…”