Читать книгу Security Engineering - Ross Anderson - Страница 27

I was in a hotel in Palo Alto, California, reading the Guardian online before a scheduled visit to Google where I'd been as a scientific visitor in 2011, helping develop contactless payments for Android phones. The headline was ‘NSA Prism program taps in to user data of Apple, Google and others’; the article, written by Glenn Greenwald and Ewen MacAskill, describes a system called Prism that collects the Gmail and other data of users who are not US citizens or permanent residents, and is carried out under an order from the FISA court [818]. After breakfast I drove to the Googleplex, and found that my former colleagues were just as perplexed as I was. They knew nothing about Prism. Neither did the mail team. How could such a wiretap have been built? Had an order been served on Eric Schmidt, and if so how could he have implemented it without the mail and security teams knowing? As the day went on, people stopped talking.

It turned out that Prism was an internal NSA codename for an access channel that had been provided to the FBI to conduct warranted wiretaps. US law permits US citizens to be wiretapped provided an agency convinces a court to issue a warrant, based on ‘probable cause’ that they were up to no good; but foreigners could be wiretapped freely. So for a foreign target like me, all an NSA intelligence analyst had to do was click on a tab saying they believed I was a non-US person. The inquiry would be routed automatically via the FBI infrastructure and pipe my Gmail to their workstation. According to the article, this program had started at Microsoft in 2007; Yahoo had fought it in court, but lost, joining in late 2008; Google and Facebook had been added in 2009 and Apple finally in 2012. A system that people thought was providing targeted, warranted wiretaps to law enforcement was providing access at scale for foreign intelligence purposes, and according to a slide deck leaked to the Guardian it was ‘the SIGAD¹ most used in NSA reporting’.

The following day we learned that the source of the story was Edward Snowden, an NSA system administrator who'd decided to blow the whistle. The story was that he'd smuggled over 50,000 classified documents out of a facility in Hawaii on a memory stick and met Guardian journalists in Hong Kong [819]. He tried to fly to Latin America on June 21st to claim asylum, but after the US government cancelled his passport he got stuck in Moscow and eventually got asylum in Russia instead. A consortium of newspapers coordinated a series of stories describing the signals intelligence capabilities of the ‘Five Eyes’ countries – the USA, the UK, Canada, Australia and New Zealand – as well as how these capabilities were not just used but also abused.

The first story based on the leaked documents had actually appeared two days before the Prism story; it was about how the FISA court had ordered Verizon to hand over all call data records (CDRs) to the NSA in February that year [815]. This hadn't got much attention from security professionals as we knew the agencies did that anyway. But it certainly got 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.