Clouds and the VPN

Question:
Do I need VPNs in the cloud?

Answer:
There are several questions regarding the necessity of VPNs in the cloud.

I think the first step is to clear the concept of cloud. Currently the word “cloud” is used interchangeably for TelCo service provider transport clouds (Network Clouds) (e.g.MPLS) and Cloud computing web services that provide resizable compute capacity as a cloud (like Amazon EC2).. We can also define private service providers like SaaS providers, managed service providers MSPs) as cloud/utility providers (like force.com from salesforce.com, webroot SaaS). Here are some articles defining cloud and transport options.
http://www.eecs.berkeley.edu/Pubs/TechRpts/2009/EECS-2009-28.pdf
http://mediaproducts.gartner.com/reprints/f5networks/vol3/article4/article4.html


When the necessity of VPNs in the clouds are analyzed, it is obvious that encryption is indeed one of the key pillars of modern information security. And VPNs do provide confidentiality and integrity for data at transit. When cloud networks do transport the data they should provide integrity and confidentiality of data. That being said this does not have to be at layer 3 (IPSEC) or layer 6 (SSL). So focusing on an IPSEC client does not help to address the issue. Confidentiality and integrity services can also be provided via applications themselves. When data is critical you may certainly encrypt data at application layer. (e.g. rights management solutions)

Here is the high level satus for VPNs in the cloud

1- TelCo Network Clouds (Service Provider) – This is the most interesting part. TelCos claim that their shared infrastructure and MPLS VPNs are secure. This is questionable (see article below) but the answer depends on the security needed.
If service provider cloud is not trusted enough you always encrypt at another layer (usually with the application).I personally believe that cloud service provider (TelCos) must be subject to heavier inspection when they are transporting almost all of the intersite traffic. Here are some articles discussing the issue
http://www.blackhat.com/presentations/bh-europe-06/bh-eu-06-Rey-up.pdf
http://www.techworld.com/networking/features/index.cfm?featureid=3360

I also do not understand why TelCos are exempt from security regulations. (PCI is a good example) TelCos (and their admins, applications, helpdesk people, servers, cable guys…) do have access to almost all interoffice data traffic when MPLS type of TelCo backbone is used. And when the MPLS cloud is compromised, all clear text (yes even the tunneled ones) will be compromised. Real encryption is rarely used. TelCos have been promoting themselves as secure service providers while promoting layered tunnels as segmentation, but I believe they must seal these claims with 3rd party certifications and allowing encryption friendly (where keys are held by the data custodians) clouds.

2- Cloud Computing providers: These providers addressed encryption at their inception thanks to their security aware generation. Before encryption there are several other questions. Here is my post on generic cloud computing security issues: http://security.24kasim.org/2009/02/cloud-computing-security.html

3- SaaS providers. SSL looks like the king at these providers. Segregation of customer data, and customer driven/controlled encrpytion for data at rest and data at transit is required. For data at transit, SSL is secure enough when proper authentication/cert management is provided.

I am still following the following basic principles when I evaluate a platform. Regardless of the nature of technology, all platforms (clouds and others) should answer properly to following areas of information security:
1- Authentication
2- Authorization
3- Confidentiality
4- Integrity
5- Non-Repudiation

cheers,
- yinal