Cloud services can be monitored for system performance but can they also be monitored for compliance? That’s one of the main questions that the Cloud Trust Protocol aims to address in 2013.
Compliance and transparency go hand in hand.
The Cloud Trust Protocol (CTP) is designed to allow cloud customers to query cloud providers in real-time about the security level of their service. This is measured by evaluating “security attributes” such as availability, elasticity, confidentiality, location of processing or incident management performance, just to name a few examples. To achieve this, CTP will provide two complementary features:
- First, CTP can be used to automatically retrieve information about the security offering of cloud providers, as typically represented by an SLA.
- Second, CTP is designed as a mechanism to report the current level of security actually measured in the cloud, enabling customers to be alerted about specific security events.
These features will help cloud customers compare competing cloud offerings to discover which ones provide the level of security, transparency and monitoring capabilities that best match the control objectives supporting their compliance requirements. Additionally, once a cloud service has been selected, the cloud customer will also be able to compare what the cloud provider offered with what was later actually delivered.
For example, a cloud customer might decide to implement a control objective related to incident management through a procedure that requires some security events to be reported back to a specific team within a well-defined time-frame. This customer could then use CTP to ask the maximum delay the cloud provider commits to for reporting incidents to customers during business hours. The same cloud customer may also ask for the percentage of incidents that were actually reported back to customers within that specific time-limit during the preceding two-month period. The first example is typical of an SLA while the second one describes the real measured value of a security attribute.
CTP is thus designed to promote transparency and accountability, enabling cloud customers to make informed decisions about the use of cloud services, as a complement to the other components of the GRC stack. Real time compliance monitoring should encourage more businesses to move to the cloud by putting more control in their hands.
From CTP 2.0 to CTP 3.0
CTP 2.0 was born in 2010 as an ambitious framework designed by our partner CSC to provide a tool for cloud customers to “ask for and receive information about the elements of transparency as applied to cloud service providers”. CSA research has begun undertaking the task of transforming this original framework into a practical and implementable protocol, referred to as CTP 3.0.
We are moving fast and the first results are already ready for review. On January 15th, CSA completed a first review version of the data model and a RESTful API to support the exchange of information between cloud customers and cloud provider, in a way that is independent of any cloud deployment model (IaaS, PaaS or SaaS). This is now going through the CSA peer review process.
Additionally, a preliminary set of reference security attributes is also undergoing peer review. These attributes are an attempt to describe and standardize the diverse approaches taken by cloud providers to expressing the security features reported by CTP. For example, we have identified more than five different ways of measuring availability. Our aim is to make explicit the exact meaning of the metrics used. For example, what does unavailability really mean for a given provider? Is their system considered unavailable if a given percentage of users reports complete loss of service? Is it considered unavailable according to the results of some automated test to determine system health?
As well as all this nice theory, we are also planning to get our hands dirty and build a working prototype implementation of CTP 3.0 in the second half of 2013.
Challenges and research initiatives
While CTP 3.0 may offer a novel approach to compliance and accountability in the cloud, it also creates interesting challenges.
To start with, providing metrics for some security attributes or control measures can be tricky. For example, evaluating the quality of vulnerability assessments performed on an information system is not trivial if we want results to be comparable across cloud providers. Other examples are data location and retention, which are both equally complex to monitor, because of the difficulty of providing supporting evidence.
As a continuous monitoring tool, CTP 3.0 is a nice complement to traditional audit and certification mechanisms, which typically only assess compliance at a specific point in time. In theory, this combination brings up the exciting possibility of a “permanently certified cloud”, where a certification could be extended in time through automated monitoring. In practice however, making this approach “bullet-proof” requires a strong level of trust in the monitoring infrastructure.
As an opportunity to investigate these points and several other related questions, CSA has recently joined two ambitious European Research projects: A4Cloud and CUMULUS. A4Cloud will produce an accountability framework for the entire cloud supply chain, by combining risk analysis, creative policy enforcement mechanisms and monitoring. CUMULUS aims to provide novel cloud certification tools by combining hybrid, incremental and multi-layer security certification mechanisms, relying on service testing, monitoring data and trusted computing proofs.
We hope to bring back plenty of new ideas for CTP!
Help us make compliance monitoring a reality!
A first draft of the “CTP 3.0 Data Model and API” is currently undergoing expert review and will then be opened to public review. If you would like to provide your expert feedback, please do get in touch!
by Alain Pannetrat
Dr. Alain Pannetrat is a Senior Researcher at Cloud Security Alliance EMEA. He works on CSA’s Cloud Trust Protocol providing monitoring mechanisms for cloud services, as well as CSA research contributions to EU funded projects such as A4Cloud and Cumulus. He is a security and privacy expert, specialized in cryptography and cloud computing. He previously worked as a IT Specialist for the CNIL, the French data protection authority, and was an active member of the Technology Subgroup of the Article 29 Working Party, which informs European policy on data protection. He received a PhD in Computer Science after conducting research at Institut Eurecom on novel cryptographic protocols for IP multicast security.