The SC article focuses on the "Fishbowl" phones designed by the NSA and includes a number of interesting comments on the state of security implementations provided by vendors. It mentions that the NSA was looking to use SSL VPNs but due to a lack of interoperability wound up using IPSEC instead. Similarly they were looking to use DTLS-SRTP, but didn't find the implementations and so instead used "descriptions". The article has this excellent statement by Salter (my emphasis added):
Salter said the security specifications, such as those sought for the voice application, would be useful to everyone.
She urged colleagues to demand vendors improve unified communications interoperability.
“We need to send a message [about] standards, interoperability and plug and play," she said.
This need for interoperability and standards support was certainly one of the themes I tried to bring out in the book. It is indeed critical for the long term success of securing unified communications systems.
I also found it interesting that the NSA encrypts the voice twice:
Voice calls are encrypted twice in accordance with NSA policy, using IPSEC and SRTP, meaning a failure requires “two independent bad things to happen,” Salter said.
While there certainly is value in having multiple layers of security, I do wonder what this means in terms of computational overhead and/or latency. As our mobile phones have become more powerful, perhaps this is no longer a major concern.
Separate from the article, I was intrigued to read over on the NSA Mobility Program page that the first document they are releasing is the "Enterprise Mobility Architecture for Secure Voice over Internet Protocol (SVoIP)". From the page:
The first Mobility Capability document to be released is the initial draft release of the Enterprise Mobility Architecture for Secure Voice over Internet Protocol (SVoIP). It is intended to be a living reference that will be updated to keep pace with technology and policies as they change over time, as additional security products and services are developed, and as lessons learned from early adopters of this architecture are applied. As a first step, this version contains guidance on the required procedures necessary to build and implement a SVoIP capability using commercial grade cellular mobile devices. Future releases will build on this architecture and will include mobile device management and data applications; and ultimately integrate the WIFI service with an expanded list of end devices.
The 100+ page PDF file looks to be a fairly comprehensive view into what is involved with rolling out a secure mobile communications solution. It's great to see this from the NSA and it is a great contribution to the ongoing efforts to secure VoIP communications.