Evolution of Distributed Policy Enforcement in the Cloud

December 10, 2013 | Leave a Comment

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?

December 9, 2013 | Leave a Comment

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

December 6, 2013 | Leave a Comment

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

December 4, 2013 | Leave a Comment

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

December 4, 2013 | Leave a Comment

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

December 3, 2013 | Leave a Comment

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

December 3, 2013 | Leave a Comment

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:

How Snowden Breached the NSA

November 20, 2013 | Leave a Comment

NOVEMBER 12TH, 2013 – BY: 

How Edward Snowden did it and is your enterprise next?

There’s one secret that’s still lurking at the NSA: How did Edward Snowden breach the world’s most sophisticated IT security organization? This secret has as much to do with the NSA as it does with your organization. In this exclusive infographic, Venafi breaks open how Edward Snowden breached the NSA. Venafi is sharing this information and challenges the NSA or Edward Snowden to provide more information so that enterprises around the world can secure their systems and valuable data.



NSA Director General Keith Alexander summed up well Snowden’s attack: “Snowden betrayed the trust and confidence we had in him.” The attack on trust, the trust that’s established by cryptographic keys and digital certificates, is what left the NSA unable to detect or respond. From SSH keys to self-signed certificates, every enterprise is vulnerable. This exclusive infographic provides you with the analysis needed to understand the breach and how it could impact you and your organization.


Edward Snowden Infographic


Learn more about how Edward Snowden compromised the NSA.

Seeing Through the Clouds

November 20, 2013 | Leave a Comment

By TK Keanini, CTO, Lancope

The economics of cyber-attacks have changed over the years. Fifteen years ago, it was all about network penetration, but today advanced attackers are more concerned about being detected. Similarly, good bank robbers are concerned about breaking into the bank, but great bank robbers have mastered how to get out of the bank without any detection.

Virtualization Skews Visibility

Because virtual-machine-to-virtual-machine (VM2VM) communications inside a physical server cannot be monitored by traditional network and security devices, the cloud can potentially give attackers more places to hide. Network and security professionals need to be asking themselves what cost-effective telemetry can be put in the cloud and across all of their networks such that the advanced persistent threat can’t escape detection.

The answer, I believe, lies in flow-based standards like NetFlow and IPFIX. Originally developed by Cisco, NetFlow is a family of standard protocols spoken by a wide variety of popular network equipment. IPFIX is a similar standard that was created by the Internet Engineering Task Force (IETF) and is based on NetFlow Version 9. These standards provide the most feasible, pervasive and trusted ledger of network activity for raising operational visibility across both physical and virtual environments.

Regaining Cloud Control

Regaining control of the cloud starts with basic awareness. Security teams need to know what applications, data and workloads are moving into cloud environments, where that data resides at any particular time, who is accessing that data and from where. They need this information in real time, and they need historical records, so that in the event that a breach is suspected it is possible to reconstruct what happened in the past. The recipe for success here is simple: leverage NetFlow or IPFIX from all of your routers, switches, firewalls and wireless access points to obtain a complete picture of everything happening across your network.

Flow-based standards like NetFlow and IPFIX provide details of every conversation taking place on the network. Some people think they need full packet capture of everything traveling on the network, and while that would be nice, it simply cannot scale. However, the metadata of that same traffic flow, as provided via NetFlow and IPFIX, does scale quite well and if need be, you can make the decision to also ‘tap’ a flow of interest to gather further intelligence.

Selecting a Monitoring Solution

By collecting and analyzing flow data, organizations can cost-effectively regain the internal visibility needed to detect and respond to advanced attacks across large, distributed networks and cloud environments. However, not all flow collection and analysis systems are created equal. It is important to determine the following when selecting a security monitoring solution for your physical and virtualized network and/or private cloud:

  1. Does the solution indeed provide visibility into virtual environments? (Some can only monitor physical infrastructure.)
  2. Are you getting an unsampled NetFlow or IPFIX feed? (Sampled flow data does not provide a complete picture of network activity.)
  3. Does the solution conduct in-depth analysis of the flow data? Is the intelligence it supplies immediately actionable?
  4. Does the solution deliver additional layers of visibility including application awareness and user identity monitoring, which can be critical for finding attackers within the network?
  5. Does the solution allow for long-term flow storage to support forensic investigations?


It is also important to conduct similar due diligence on the security technologies and practices used by various providers if you decide to outsource your IT services to the public cloud.


Thwarting Advanced Attacks


As the CTO of Lancope, it is my goal to ensure that the bad guys cannot persist on your networks. No matter which stage you are in with your cloud strategy –whether virtualizing your infrastructure, or using a public or private cloud – the collection and analysis of existing flow data can dramatically enhance your security. When every router/switch/wireless access point/firewall is reporting unsampled flow records, and you are able to synthesize that data into actionable intelligence, there is just nowhere for the adversary to hide.


For more details on NetFlow for security, check out the Lancope blog or follow me on Twitter @tkeanini.


TK Keanini is a Certified Information Systems Security Professional (CISSP) who brings nearly 25 years of network and security experience to his role of CTO at Lancope. He is responsible for leading Lancope’s evolution toward integrating security solutions with private and public cloud-based computing platforms.

Cloud Collaboration: Maintaining Zero Knowledge across International Boundaries

November 20, 2013 | Leave a Comment

The increasingly global nature of business requires companies to collaborate more and more across borders, exchanging all manner of documents: contracts, engineering documents and other intellectual property, customer lists, marketing programs and materials, and so on. Unfortunately, the combination of recent NSA revelations and new European regulations are likely to make the challenge of securing business data even more difficult than it already is.It is therefore likely that new approaches will be needed that more easily allow trust across borders for confidential document exchange.

Evolving Regulatory Environments

Data shared across national boundaries may be subject to multiple legal frameworks depending on the nature of the information. The regulatory environment in the European Union is evolving significantly, with countries working to update their laws and regulations to protect citizens’ electronic data, even when it is held outside the EU. This includes almost everything a person might post to the Internet, including photos, blogs and so on. The concern is that the EU will strengthen their regulations to a level that will be extremely difficult and expensive for companies to comply with.

There is currently an agreement with the EU(“Safe Harbor”) that US companies can voluntarily participate in if they are holding EU citizens’ data. That agreement could be replaced by much more stringent requirements, though they will not take effect before 2016. US companies are required to implement a number of protections for citizen data under the EU agreement, and there is no provision that allows them to release personal data to the government.

All of these developments were in play before the Edward Snowden revelations took place. Since then, European attitudes on data privacy have hardened even further.In the meantime, attitudes in the rest of the world towards US-based service providers have also soured. To make matters worse, the Snowden information leaks not only exposed “NSA snooping”, it also raised suspicions that some vendor equipment and standardized algorithms may have been compromised with backdoors or weaknesses.

New Reality is Impacting Cloud Sharing

Meanwhile, organizations are seeking to leverage cloud computing as much as possible for business agility and cost control reasons. The natural choice will be to use a cloud-based document sharing provider for external collaboration.  A big reason for this is that business partners need to update documents, not just read them. Granting such access to data inside an organization’s data center is problematic from both a security and administrative perspective.

Given this quagmire, organizations that want to use a cloud provider for external collaboration across international boundaries have two choices, both of which are problematic:

  • US Provider: This is a good option for organizations that prefer to use a well-established provider, are not worried about the government or NSA accessing their content and are not concerned about equipment backdoors.But it may not be acceptable to your international business partners.
  • Non-US Provider: This approach may appeal to organizations that want to allay concerns expressed by their foreign partners, especially those in Europe, about US government access to their data. However, a European operator is unlikely to be as well established as a US cloud provider, US businesses will not have any realistic leverage with them and foreign governments are known to dabble in data interception themselves. Finally, depending on who the organization is doing business with, they may face resistance from a non-European partner not willing to use a European cloud provider.

Given these alternatives, some organizations may be tempted to just give up and keep data internal. This approach reintroduces the security and management headaches that most companies were trying to eliminate by adopting cloud sharing in the first place. It also poses a problem for the organization’s partners because they will need to manage a different access model for every business with which they collaborate.

Federation May be the Answer

Fortunately, new federated encryption and key management technologies have emerged to addresses these problems. As a starting point, consider encryption. Crypto is an obvious solution to the cloud provider dilemma for international collaboration. If the data is encrypted then it should be protected from unauthorized access. In reality, it’s not that simple.

In most environments, the cloud provider is performing the encryption. As a result, the provider could receive a lawful request to access data under their control or their systems could be compromised. Both would result in a data breech. Furthermore, some providers may not encrypt data end-to-end. This fact alone may cause European organizations to balk, particularly if regulated data is involved.

There are other options that move control of encryption keys into the hands of data owners. However, most require a “trusted third party” to handle encryption support services such as key management, opening another hole, and inviting problems with European regulations.

Replacing Trust with Trustworthiness

A new class of federation and mediation technologies offers the best hope for cross-border encryption. In this model, the central cloud service provider does not need to be “trusted”. Instead, they serve a “mediator” to facilitate secure document collaboration, but do not have the necessary data access privileges or keys to actually decrypt files or access them in an unencrypted form.

This architecture consists of a mediator and two or more end-user software elements, and works as follows:

  • The central (cloud-based) mediator receives enrollment requests from the various users who want to collaborate. No distinction is made between the users based on location – they can be anywhere.
  • The meditator enrolls these users into a cryptographically protected group, and establishes a data repository for the documents that will be shared. Using advanced key management techniques, the relevant key material is fragmented, re-encrypted and distributed. As a result, the mediator does not end up with enough key material to decrypt anything, and each user must have the “approval” of the mediator to decrypt documents in the group repository. Note that because documents are initially encrypted at the end stations and the mediator cannot decrypt them, this architecture has removed the need for a “trusted third party” in the cloud.
  • As users submit documents into the shared repository, these are encrypted and the activity logged.
  • When any user tries to access a document, they submit their (cryptographically authenticated) credentials to the mediator. If they mediator concurs that the request is valid, a portion of key material is released to the requesting user. This missing key fragment plus the user’s own key material, allow the document to be decrypted.

Advancing Security through Mediation

Besides delivering confidentiality, this federated architecture offers advanced services that basic encryption facilities do not. The key enabler is the mediation function: since it serves as gatekeeper for data access. Using the mediator, business partners can pre-agree on special conditions for document access, in addition to the normal release that takes place when participating users authenticate themselves to the system.

As a simple example, access revocation becomes trivial. If the group agrees to revoke a person’s access to documents, the mediator can be instructed to deny access to that person, and immediately this request is implemented, since the mediator must approve all document release. Contrast this with certificate revocation, which can take a significant amount of time before actually terminating access.

For a more powerful example, let’s assume that collaborating companies agree that they want to ensure that if their participating end-user is on vacation or leaves the company, protected documents can still be accessed. Using the mediator, they would establish a cryptographically protected “release circuit,” which would authorize document access when a combination of other staff agrees.

A typical example might be the combination of a member of the executive team, an IT administrator, and a representative from HR.  A member of all three teams would need to authorize the release using a cryptographically secure process. Only then would the document be decrypted and delivered to whomever the team selects. The mediator logs all this activity in an encrypted, centralized log facility. Since all participants can audit activity,there’s no risk of a rogue IT person compromising the logs.

A federated architecture also supports controlled access within documents for searching and eDiscovery.  When an end-station encrypts a file, it can also extract metadata (including keywords, revision history, etc.), encrypt that metadata using a different set of keys, and pass it to the mediator for storage. As with the document itself, mediators on their own cannot decrypt the metadata. However, mediators can implement a [circuit] for metadata release. For example, business partners could agree that a combination of an executive and an IT person at any collaborating firm can “unlock” the metadata, so that they can being an eDiscovery search or security investigation. Once they find the document subset of interest (if any), they can initiate the (more restrictive) document release process on just those files. In this way, the companies involved can still meet their data governance requirements without compromising overall security.


Privacy concerns and emerging government regulations are making secure document sharing across international boundaries significantly more difficult and expensive to implement. This threatens the ability of organizations to move to cloud-based solutions, decreasing agility and efficiency. Fortunately, new security architectures such as federated and mediated encryption are capable of meeting these challenges. Like all privacy systems, such technologies must be properly deployed and maintained to be effective. Since they eliminate the need for a trusted third party in the cloud, they offer the best hope for establishing a trustworthy framework for secure document collaboration locally or internationally.

About the Author: Jonathan Gohstand is an expert in security and virtualization technologies, and Vice President of Products & Marketing at AlephCloud, a provider of cloud content privacy solutions.