http://www.cryptogon.com/?p=45500
Recently disclosed documents show that the NSA’s fourth-largest cable tapping program, codenamed INCENSER, pulls its data from just one single source: a submarine fiber optic cable linking Asia with Europe.
Until now, it was only known that INCENSER was a sub-program of WINDSTOP and that it collected some 14 billion pieces of internet data a month. The latest revelations now say that these data were collected with the help of the British company Cable & Wireless (codenamed GERONTIC, now part of Vodafone) at a location in Cornwall in the UK, codenamed NIGELLA.
For the first time, this gives us a view on the whole interception chain, from the parent program all the way down to the physical interception facility. Here we will piece together what is known about these different stages and programs from recent and earlier publications.
…
Interception equipment
How the actual interception takes place, can be learned from an article in The Guardian from June 2013, which provides some details about the highly sophisticated computer equipment at cable tapping points.
First, the data stream is filtered through what is known as MVR (Massive Volume Reduction), which immediately rejects high-volume, low-value traffic, such as peer-to-peer downloads. This reduces the volume by about 30%.
Selectors
The next step is to pull out packets of information that contain selectors like phone numbers and e-mail, IP and MAC addresses of interest. In 2011, some 40,000 of these were chosen by GCHQ and 31,000 by the NSA, according to The Guardian. This filtering is most likely done by devices from Boeing-subsidiary Narus, which can analyse high-volume internet traffic in real-time.
A single NarusInsight machine can monitor traffic up to 10 Gigabit/second, which means there have to be up to a dozen of them to filter the relevant traffic from the FA1 and FEA submarine cables. Most of the information extracted in this way is internet content, such as the substance of e-mail messages.
Full sessions
Besides the filtering by using specific selectors, the data are also sessionized, which means all types of IP traffic, like VoIP, e-mail, web mail and instant messages are reconstructed. This is something the Narus devices are also capable of.
These “full take” sessions are stored as a rolling buffer on XKEYSCORE servers: content data for only three to five days, and metadata for up to 30 days. But “at some sites, the amount of data we receive per day (20+ terabytes) can only be stored for as little as 24 hours” according to an NSA document from 2008.
The aim is to extract the best 7,5% of the traffic that flows past the access, which is then “backhauled” from the tapping point to GCHQ Bude through two 10 gigabit/s channels (the “egress” capacity).
Recently disclosed documents show that the NSA’s fourth-largest cable tapping program, codenamed INCENSER, pulls its data from just one single source: a submarine fiber optic cable linking Asia with Europe.
Until now, it was only known that INCENSER was a sub-program of WINDSTOP and that it collected some 14 billion pieces of internet data a month. The latest revelations now say that these data were collected with the help of the British company Cable & Wireless (codenamed GERONTIC, now part of Vodafone) at a location in Cornwall in the UK, codenamed NIGELLA.
For the first time, this gives us a view on the whole interception chain, from the parent program all the way down to the physical interception facility. Here we will piece together what is known about these different stages and programs from recent and earlier publications.
…
Interception equipment
How the actual interception takes place, can be learned from an article in The Guardian from June 2013, which provides some details about the highly sophisticated computer equipment at cable tapping points.
First, the data stream is filtered through what is known as MVR (Massive Volume Reduction), which immediately rejects high-volume, low-value traffic, such as peer-to-peer downloads. This reduces the volume by about 30%.
Selectors
The next step is to pull out packets of information that contain selectors like phone numbers and e-mail, IP and MAC addresses of interest. In 2011, some 40,000 of these were chosen by GCHQ and 31,000 by the NSA, according to The Guardian. This filtering is most likely done by devices from Boeing-subsidiary Narus, which can analyse high-volume internet traffic in real-time.
A single NarusInsight machine can monitor traffic up to 10 Gigabit/second, which means there have to be up to a dozen of them to filter the relevant traffic from the FA1 and FEA submarine cables. Most of the information extracted in this way is internet content, such as the substance of e-mail messages.
Full sessions
Besides the filtering by using specific selectors, the data are also sessionized, which means all types of IP traffic, like VoIP, e-mail, web mail and instant messages are reconstructed. This is something the Narus devices are also capable of.
These “full take” sessions are stored as a rolling buffer on XKEYSCORE servers: content data for only three to five days, and metadata for up to 30 days. But “at some sites, the amount of data we receive per day (20+ terabytes) can only be stored for as little as 24 hours” according to an NSA document from 2008.
The aim is to extract the best 7,5% of the traffic that flows past the access, which is then “backhauled” from the tapping point to GCHQ Bude through two 10 gigabit/s channels (the “egress” capacity).
