Evolution of Distributed Policy Enforcement in the Cloud

By Krishna Narayanaswamy, chief scientist at Netskope






As computing shifts to the cloud, so too must the way we enforce policy.

Until recently, enterprise applications were hosted in private data centers under the strict control of centralized IT. Between firewalls and intrusion prevention systems, IT was able to protect the soft inner core of enterprise information from external threats. Ever more sophisticated logging and data leakage prevention solutions supplemented those with a layer of intelligence to help IT identify and prevent not only external but also internal threats that led to costly data breaches. Even remote workers were shoe-horned into this centralized model using VPN technology so they can be subjected to the same security enforcement mechanisms.

The cloud has brought so many benefits, with users of compute services being able to procure the service that best fits their needs, independent of the others, and providers able to focus on what they do well, whether building scalable infrastructure or solving a business problem with a software service. The distributed nature of the cloud also means that users enjoy the availability and performance benefits of multiple redundant data centers. The model also aligns well with the proliferation of smart devices and users’ need to access content anywhere, anytime.

But as computing has moved to the cloud – and we are now at a tipping point with nearly one-third of compute spend reported to be on cloud infrastructure, platform, and software services – legacy security architectures are quickly becoming ineffective.

We need a fresh way to solve the problem. But first a short primer on security policy enforcement:

Security reference architectures consist of two components: the Policy Control Point (PCP) and Policy Enforcement Point (PEP). The PCP is where security policies are defined. In general, there is one or a small number of PCPs in an enterprise. The PEP is where the security policies are enforced. Typically there are many PEPs in an enterprise network, and a group of PEPs may enforce a specific type of policy.

The way it works is the PCP updates the many PEPs with the specific policy rules that pertain to the PEPs’ capabilities. The PEPs, for their part, act in real-time on the policy trigger, such as discovering data passing through a network and enforcing the policy as a pre-defined triggered action happens. PEPs that experience a policy trigger then send policy event logs back to the PCP to convey the attempted policy violation and confirm enforcement for compliance reporting purposes. Event logs provide information from the PEP about how and when the policy was triggered that can be used to create new or tune existing policies.In practice, the PCP and PEPs are usually not a single physical entity but a collection of physical entities that provide the logical functions described above.


What are the key requirements for a cloud security framework?

The fact that enterprises’ applications, platform, and infrastructure servicesare moving to the cloud breaks the notion of a centralized service delivery point.Cloud service providers have optimized their ownsolutions for the specific types of services they’re offering or enabling, e.g., CRM, backup, storage, etc.This means that there are no common security controls across all of the services that enterprises are accessing.

Adding insult to injury, enterprises have another dimension of complexity to deal with: They need to plan for users to get both on-premand off-prem access to enterprise apps, as well as access from corporate-owned and personalsystems and a plethora of mobile devices. And in the face of all of this complexity, of course, the service and the policy enforcement needs to be efficient, as transparent as possible, and “always on.”

A tall order.

What are the ways to ensure this?

One possibility is the status quo: Ensure that all access to cloud services from any device, whether corporate-owned or BYOD are backhauled to the enterprise datacenter where the PEPs are deployed. This approach creates an hour-glassconfiguration where traffic from differentaccess locations is funneled to a choke-point and then fans out to the eventual destination, which is generally all over the Internet. Great for policy enforcement. Not so much for user experience.

Another possibility is to enforce policies at the server end. This is more efficient from a traffic standpoint, but isn’t effective because every cloud serviceprovider has a proprietary policy framework and different levels of policy enforcement capabilities. This means the PCP has to be able to convert the configuredpolicies to the specific construct supported by each service provider.


A third possibility: Distributed cloud enforcement (in case you haven’t guessed it yet, this is the recommended one). This involves distributing PEPs in the cloud so that traffic can be inspected for both analytics and policy triggers, irrespective of where it originates. It also means that PEPs will be deployed close to user locations, allowing for minimal traffic detours enroute to theapplication hosted by the cloud service provider. The distributed PEPs are controlled by a central PCP entity. This all sounds very easy, and of course, the devil is in the details.

In order to do this right, the solution enforcing the policies must employ efficient steering mechanisms in order to get traffic to the PEPs in the cloud. The PEPs must enforce enterprises’ security policies accurately and quickly, and send those policy logs to the PCP in a secure, reliable way each and every time. This reference architecture resembles legacy architecture in terms of the level of control it provides while obviating the need to backhaul traffic back to the enterprise datacenter. The PEP only has to provide the various security functions that were deployed in the datacenter: access control, data loss prevention, anomaly detection, etc.The architecture also provides an option for introducing new services that are relevant to the emerging trends. For example, with corporate data moving to the cloud which is not in the direct control of the enterprise, data protection becomes an important requirement. The cloud resident PEP scan provide encryption functionality to address this requirement, among other non-security capabilities such as performance, SLA, and cost measurements.


It’s clear that emerging trends like cloud and BYOD have obviated existing security architectures.We are not alone in addressing this issue. Organizations such as the Cloud Security Alliance, which recently kicked off its Software Defined Perimeter (SDP) initiative, are looking hard at the best ways to tackle this. I submit that addressing the above trends with a distributed cloud policy enforcement framework meets key requirements and provides a foundation for adding new security (and non-security) services that will become relevant in the near future.

What’s New With the Security as a Service Working Group?

CSA members are invited to join the Security-as-a-Service Working Group (SecaaS WG) which aims to promote greater clarity in the Security as a Service model.

Why a Security as a Service Working Group?

Numerous security vendors are now leveraging cloud based models to deliver security solutions. This shift has occurred for a variety of reasons including greater economies of scale and streamlined delivery mechanisms. Regardless of the motivations for offering such services, consumers are now faced with evaluating security solutions which do not run on premises. Consumers need to understand the unique nature of cloud delivered security offerings so that they are in a position to evaluate the offerings and to understand if they will meet their needs.

Research from this working group aims to identify consensus definitions of what Security as a Service means, to categorize the different types of Security as a Service and to provide guidance to organizations on reasonable implementation practices.

Ongoing Research

As part of its charter, the group expects to publish three key pieces of research related to the Security as a Service model over the course of the following six months

1. A Category Framework Proposal. This will include business and technical elements as well as a survey on this framework proposal and how it applies to existing categories

2. Categories of Service v2.0. This document will include sections based off of the new framework

3. Implementation Documents v2.0,. These implementation documents will include templates based off of the new framework as well business and technical elements as well as a detailed guidance.

To get involved, visit the SecaaS Working Group page.



CloudTrust Protocol (CTP) Working Group Kicks Off at CSA Congress

The Cloud Trust Protocol (CTP) aims to provide a protocol to enable Cloud Users to query Cloud Providers in real time about the security level of their service. It aims to foster transparency and trust in the cloud supply chain, bringing greater visibility to cloud users and providing them with data on a continuous basis in order to inform their daily risk management decisions.

As a monitoring mechanism, CTP also ambitions to become the pillar of CSA’s future continuous-monitoring based certification, complementing the STAR third party certification and attestation in the Open Certification Framework.

Earlier this fall, Cloud Security Alliance launched the CTP Working Group. The goal of the Working Group is to leverage the initial idea of Ron Knode and turn CTP into close to market solution in the next 18 months, drawing both on recent research conducted by the CSA EMEA Research team and on the inputs of leading stakeholders in the cloud industry, including both providers and users.

The CTP Working Group’s mission is to refine, challenge and extend the existing CTP framework and API specification, establish standard monitored cloud security attributes, implement a pilot and assure the proper integration of CTP in the Open Certification Framework.

The CTP Working Group will be chaired by the following people:

  • John DiMaria – British Standards Institute
  • Tim Sandage – Amazon Web Services
  • Sandeep Singh – Dell

Dr Alain Pennetrat, Senior Researcher at the CSA EMEA, will be the WG Technical Lead.

For more information, visit https://cloudsecurityalliance.org/research/ctp/.  We’ll announce the official kick-off call within the next month.

Introducing the CSA Financial Services Working Group

At our annual CSA Congress today, the CSA is pleased to introduce the new Financial Services Working Group (FSWG), which aims to provide knowledge and guidance on how to deliver and manage secure cloud solutions in the financial industry, and to foster cloud awareness within the sector and related industries. It will complement, enrich and customize the results of other CSA WG in a way to provide a sector specific guidance.

Why a financial services working group?

Financial services organizations have specific, often unique requirements regarding security, privacy and compliance. The Financial Services Working Group’s main objective is the identify and share the challenges, risks and best practices for the development, deployment and management of secure cloud services in the financial and banking industry.

Research from this working group aims to accelerate the adoption of secure cloud services in the financial industry by enabling the adoption of best practices by:

  • Identifying and sharing the industry’s main concerns regarding the delivery and management of cloud services in their sector.
  • Identifying industry needs and requirements (both technical and regulatory)
  • Identifying adequate strategic security approaches to ensure protection of business processes and data in the cloud.
  • Reviewing existing CSA research and identify potential gaps from the financial services standpoint.

Initial Research

As part of its charter, the group expects to publish four key pieces of research related to the financial services industry:

  1. A survey of existing & potential cloud solutions (products and services) in the banking and financial services sector
  2. Technical and regulatory requirements in the sector
  3. Identification and assessment of risks in cloud solutions in the sector, including interaction with other approaches such as mobile computing, social computing, and big data.
  4. Recommendations and best practices of cloud solutions for the sector.

For more information about the working group, visit https://cloudsecurityalliance.org/research/financialservices



Introducing the CSA’s Anti-Bot Working Group

Among the many exciting new working groups being established and meeting at CSA Congress, today we’d like to also introduce our Anti-Bot Working Group. Chaired by Shelbi Rombout from USBank, this group’s mission is to develop and maintain a research portfolio providing capabilities to assist the cloud provider industry in taking a lifecycle approach to botnet prevention.

Why an anti-bot group?

Botnets have long been a favored attack mechanism of malicious actors.  A recent evolution in botnet innovation has been the introduction of server-based bots as an alternative to single user personal computers.  The access to vastly greater upload bandwidths and higher compute performance has attracted the same adversaries who have built and operated earlier botnets.

As cloud computing is rapidly becoming the primary option for server-based computing and hosted IT infrastructure, CSA as the industry leader has an obligation to articulate solutions to prevent, respond and mitigate against botnets occurring on cloud infrastructure.  The CSA Anti-Bot Working Group is the primary stakeholder for coordinating these activities.

Initial Research

As part of its charter, the group expects to publish two key pieces of research related to botnets – Fundamental Anti-Bot Practices for Cloud Providers, and an Anti-Bot Toolkit Repository for Cloud Providers.

For more information about the working group, visit:  https://cloudsecurityalliance.org/research/antibot

Introducing the CSA’s New Virtualization Working Group

There’s been a lot of noise around the establishment of new working groups at this year’s Congress and today we’d like to also introduce another important addition: the Virtualization Working Group. Chaired by Kapil Raina of Zscaler, the Virtualization Working Group is chartered to lead research into the combined virtualized operating system and SDN technologies.  The group will build upon existing Domain 13 research and provide more detailed guidance as to threats, architecture, hardening and recommended best practices.

Why a Virtualization Working Group?

Virtualization is a critical part of cloud computing. Virtualization provides an important layer of abstraction from physical hardware, enabling the elasticity and resource pooling commonly associated with cloud. Virtualized operating systems are the backbone of Infrastructure as a Service (IaaS).

The CSA Security Guidance for Critical Areas of Focus in Cloud Computing focused exclusively on virtualized operating systems in Domain 13. Recent developments in software defined networking (SDN) show great potential to virtualize data networks in the same way that operating systems have been virtualized. Additionally, the future integration and potential convergence of virtualization of operating systems and networks promise to greatly impact the next generation of cloud architectures. The security issues and recommended best practices of this broader view of virtualization merit additional focused research from a reconstituted version of the CSA Virtualization Working Group.

Initial Research

As part of its charter, the CSA Virtualization Working group plans to publish a Domain 13 Virtualization Whitepaper as part of the CSA Security Guidance for Critical Areas of Focus in Cloud Computing. The paper is scheduled for release at the upcoming RSA Conference taking place in February.

For more information about the working group, visit https://cloudsecurityalliance.org/research/virtualization/


Announcing the Consensus Assessments Initiative Questionnaire (CAIQ) V.3 Open Review Period

At CSA Congress 2013 this week we are announcing the open review period of the Consensus Assessments Initiative Questionnaire (CAIQ) v.3 and we hope you will take a few moments and provide your input to this very important initiative.  Lack of security control transparency is a leading inhibitor to the adoption of cloud services. The Cloud Security Alliance Consensus Assessments Initiative (CAI) was launched to perform research, create tools and create industry partnerships to enable cloud computing assessments.

About CAIQ

The CSA is focused on providing industry-accepted ways to document what security controls exist in IaaS, PaaS, and SaaS offerings, providing security control transparency. CAIQ, by design, is integrated with and will support other projects from our research partners.   The CAIQ Questionnaire is available in spreadsheet format, and provides a set of questions a cloud consumer and cloud auditor may wish to ask of a cloud provider. It provides a series of “yes or no” control assertion questions which can then be tailored to suit each unique cloud customer’s evidentiary requirements.

This question set is meant to be a companion to the CSA Guidance and the CSA Cloud Controls Matrix (CCM), and these documents should be used together.  This question set is a simplified distillation of the issues, best practices and control specifications from our Guidance and Controls Matrix, intended to help organizations build the necessary assessment processes for engaging with cloud providers.  The Consensus Assessments Initiative is part of the CSA GRC Stack.

What’s New and Why we Need YOUR Input:

Now in its third version, the Cloud Assessments Initiative Working Group will start the open review period for a set of questions intended to help organizations further build the necessary assessment processes for engaging with cloud providers.

We are in need of input from the cloud community on a number of fronts. First, we would like input on the current CAIQ questions:  are these questions still relevant to cloud security; are they written in a way that is easy for all stakeholders to understand, and should they remain important questions to ask during the cloud assessment process.

Second, we would like to have input on what questions should be added to the assessment to help strengthen the process overall for each domain.  Finally, as CAIQ is a companion to the recently updated CCM V.3, we are seeking input on what questions should be added to two new control domains, Mobile Security and Interoperability and Portability.

As a side, the new CAIQ is now color coded to match the CCM V.3 domains for easy review.

ACTION: The open review period ends on January 6, 2013

This is your opportunity to provide feedback and comments to the v.3 of CAIQ.  Submitting feedback is easy with our 3-step process. Follow the link below to the CSA Interact peer review site:


Thank you in advance for your time and contribution.  We look forward to your input.  If you have any questions, you can contact us by emailing [email protected].

Feel free to reference the following CCM documents during your review: