Security Engineering. Ross Anderson

Garfinkel and Eugene Spafford in 1996 [753], while the classic on Internet security by Bill Cheswick and Steve Bellovin [222] gives many examples of network attacks on Unix systems.

      Carl Landwehr gives a useful reference to many of the flaws found in operating systems in the 1960s through the 1980s [1131]. One of the earliest reports on the subject (and indeed on computer security in general) is by Willis Ware in 1970 [1990]; Butler Lampson's seminal paper on the confinement problem appeared in 1970s [1127] and three years later, another influential early paper was written by Jerry Saltzer and Mike Schroeder [1642]. The textbook we get our students to read on access control issues is Dieter Gollmann's ‘Computer Security’ [780]. The standard reference on Intel's SGX and indeed its CPU security architecture is by Victor Costan and Srini Devadas [479].

      The field of software security is fast-moving; the attacks change significantly (at least in their details) from one year to the next. The classic starting point is Gary McGraw's 2006 book [1268]. Since then we've had ROP attacks, Spectre and much else; a short but useful update is Matthias Payer's Software Security [1506]. But to really keep up, it's not enough to just read textbooks; you need to follow security conferences such as Usenix and CCS as well as the security blogs such as Bruce Schneier, Brian Krebs and – dare I say it – our own lightbluetouchpaper.org. The most detail on the current attacks is probably in Google's Project Zero blog; see for example their analysis of attacks on iPhones found in the wild for an insight into what's involved in hacking modern operating systems with mandatory access control components [205].

Notes

      1 1 Microsoft had had more ambitious plans; its project Palladium would have provided a new, more trusted world for rights-management apps, alongside the normal one for legacy software. They launched Information Rights Management – DRM for documents – in 2003 but corporates didn't buy it, seeing it as a lock-in play. A two-world implementation turned out to be too complex for Vista and after two separate development efforts it was abandoned; but the vision persisted from 2004 in Arm's TrustZone, which I discuss below.

      2 2 The trust-on-first-use model goes back to the 1990s with the Java standard J2ME, popularised by Symbian, and the Resurrecting Duckling model from about the same time. J2ME also supported trust-on-install and more besides. When Apple and Android came along, they initially made different choices. In each case, having an app store was a key innovation; Nokia failed to realise that this was important to get a two-sided market going. The app store does some of the access control by deciding what apps can run. This is hard power in Apple's case, and soft power in Android's; we'll discuss this in the chapter on phones.

      3 3 There are a few exceptions: corporates can get signing keys for internal apps, but these can be blacklisted if abused.

      4 4 I'll discuss fusible links in the chapter on tamper resistance, and iPhone PIN retry defeats in the chapter on surveillance and privacy.

      5 5 Now owned by HP

      6 6 They had been developed on a crash programme to save market share following the advent of RISC processors and the market failure of the iAPX432.

      7 7 The best defence against ROP attacks in 2019 appears to be Apple's mechanism, in the iPhone X3 and later, for signing pointers with a key that's kept in a register; this stops ROP attacks as the attacker can't guess the signatures.

      8 8 Full disclosure: this was developed by a team of my colleagues at Cambridge and elsewhere, led by Robert Watson.

      9 9 In rare cases even human transmission can make malware spread quickly: an example was the ILoveYou worm which spread itself in 2000 via an email with that subject line, which caused enough people to open it, running a script that caused it to be sent to everyone in the new victim's address book.

      10 10 Rust emerged from Mozilla research in 2010 and has been used to redevelop Firefox; it's been voted the favourite language in the Stack Overflow annual survey from 2016–2019.