the attention of lawyers and politicians, as it broke during the Privacy Law Scholars' Conference and showed that US Director of National Intelligence James Clapper had lied to Congress when he'd testified that the NSA collects Americans' domestic communications ‘only inadvertently’. And what was to follow changed everything.
2.2.1.2 Tempora
On June 21st, the press ran stories about Tempora, a program to collect intelligence from international fibre optic cables [1201]. This wasn't a complete surprise; the journalist Duncan Campbell had described a system called Echelon in 1988 which tapped the Intelsat satellite network, keeping voice calls on tape while making metadata available for searching so that analysts could select traffic to or from phone numbers of interest [375, 376] (I'll give more historical background in section 26.2.6). Snowden gave us an update on the technology. In Cornwall alone, 200 transatlantic fibres were tapped and 46 could be collected at any one time. As each of these carried 10Gb/s, the total data volume could be as high as 21Pb a day, so the incoming data feeds undergo massive volume reduction, discarding video, news and the like. Material was then selected using selectors – not just phone numbers but more general search terms such as IP addresses – and stored for 30 days in case it turns out to be of interest.
The Tempora program, like Echelon before it, has heavy UK involvement. Britain has physical access to about a quarter of the Internet's backbone, as modern cables tend to go where phone cables used to, and they were often laid between the same end stations as nineteenth-century telegraph cables. So one of the UK's major intelligence assets turns out to be the legacy of the communications infrastructure it built to control its nineteenth-century empire. And the asset is indeed significant: by 2012, 300 analysts from GCHQ, and 250 from the NSA, were sifting through the data, using 40,000 and 31,000 selectors respectively to sift 600m ‘telephone events’ each day.
2.2.1.3 Muscular
One of the applications running on top of Tempora was Muscular. Revealed on October 30th, this collected data as it flowed between the data centres of large service firms such as Yahoo and Google [2020]. Your mail may have been encrypted using SSL en route to the service's front end, but it then flowed in the clear between each company's data centres. After an NSA PowerPoint slide on ‘Google Cloud Exploitation’ was published in the Washington Post – see figure 2.1—the companies scrambled to encrypt everything on their networks. Executives and engineers at cloud service firms took the smiley as a personal affront. It reminded people in the industry that even if you comply with warrants, the agencies will also hack you if they can. It made people outside the industry stop and think: Google had accreted so much access to all our lives via search, mail, maps, calendars and other services that unrestricted intelligence-service access to its records (and to Facebook's and Microsoft's too) was a major privacy breach.
Two years later, at a meeting at Princeton which Snowden attended in the form of a telepresence robot, he pointed out that a lot of Internet communications that appear to be encrypted aren't really, as modern websites use content delivery networks (CDNs) such as Akamai and Cloudflare; while the web traffic is encrypted from the user's laptop or phone to the CDN's point of presence at their ISP, it isn't encrypted on the backhaul unless they pay extra – which most of them don't [87]. So the customer thinks the link is encrypted, and it's protected from casual snooping—but not from nation states or from firms who can read backbone traffic.
Figure 2.1: Muscular – the slide
2.2.1.4 Special collection
The NSA and CIA jointly operate the Special Collection Service (SCS) whose most visible activity may be the plastic panels near the roofs of US and allied embassies worldwide; these hide antennas for hoovering up cellular communication (a program known as ‘Stateroom’). Beyond this, SCS implants collection equipment in foreign telcos, Internet exchanges and government facilities. This can involve classical spy tradecraft, from placing bugs that monitor speech or electronic communications, through recruiting moles in target organisations, to the covert deployment of antennas in target countries to tap internal microwave links. Such techniques are not restricted to state targets: Mexican drug cartel leader ‘El Chapo’ Guzman was caught after US agents suborned his system administrator.
Close-access operations include Tempest monitoring: the collection of information leaked by the electromagnetic emissions from computer monitors and other equipment, described in 19.3.2. The Snowden leaks disclose the collection of computer screen data and other electromagnetic emanations from a number of countries' embassies and UN missions including those of India, Japan, Slovakia and the EU2.
2.2.1.5 Bullrun and Edgehill
Special collection increasingly involves supply-chain tampering. SCS routinely intercepts equipment such as routers being exported from the USA, adds surveillance implants, repackages them with factory seals and sends them onward to customers. And an extreme form of supply-chain tampering was when the NSA covertly bought Crypto AG, a Swiss firm that was the main supplier of cryptographic equipment to non-aligned countries during the Cold War; I tell the story in more detail later in section 26.2.7.1.
Bullrun is the NSA codename, and Edgehill the GCHQ one, for ‘crypto enabling’, a $100m-a-year program of tampering with supplies and suppliers at all levels of the stack. This starts off with attempts to direct, or misdirect, academic research3; it continued with placing trusted people on standards committees, and using NIST's influence to get weak standards adopted. One spectacular incident was the Dual_EC_DRBG debacle, where NIST standardised a random number generator based on elliptic curves that turned out to contain an NSA backdoor. Most of the actual damage, though, was done by restrictions on cryptographic key length, dovetailed with diplomatic pressure on allies to enforce export controls, so that firms needing export licenses could have their arms twisted to use an ‘appropriate’ standard, and was entangled with the Crypto Wars (which I discuss in section 26.2.7). The result was that many of the systems in use today were compelled to use weak cryptography, leading to vulnerabilities in everything from hotel and car door locks to VPNs. In addition to that, supply-chain attacks introduce covert vulnerabilities into widely-used software; many nation states play this game, along with some private actors [892]. We'll see vulnerabilities that result from surveillance and cryptography policies in one chapter after another, and return in Part 3 of the book to discuss the policy history in more detail.
2.2.1.6 Xkeyscore
With such a vast collection of data, you need good tools to search it. The Five Eyes search computer data using Xkeyscore, a distributed database that enables an analyst to search collected data remotely and assemble the results. Exposed on July 31 2013, NSA documents describe it as its “widest-reaching” system for developing intelligence; it enables an analyst to search emails, SMSes, chats, address book entries and browsing histories [816]. Examples in a 2008 training deck include “my target speaks German but is in Pakistan. How can I find him?” “Show me all the encrypted Word documents from Iran” and “Show me all PGP usage
