Tech troubles
The Information Assurance Directorate ran into a string of problems during the build due to a lack of interoperability between vendor products.
Salter said a lack of interoperability between SSL VPN options forced designers to use IPSEC.
Several other compromises were made but none that reduced the security of the phone, Salter said.
“We needed a voice app that did DTLS (Datagram Transport Layer Security), Suite B and SRTP (Secure Real-time Transport Protocol) and we couldn’t buy it,” Salter said. “But the industry was thinking more aboutsession description … so we went with that.”
Fishbowl encryption
Designers were also challenged by the functionality in commercial products. Vendors were chosen not by reputation or preference, but by their support of required functionality. Each was plotted on a grid and chosen by “drawing a line through the list”.
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.
All traffic from the phone is routed through the enterprise as a primary security design goal.
“If we let it go to all kinds of places, we lost control of figuring out what the phone was doing. If I want pizza, I have to go through the enterprise which has to route me to Pizza Hut.”
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.
She said the Android operating system and key store were customised to be made secure enough for top secret conversations, and a “kind of police app” was designed to monitor operations on the device.