Usable Security: History, Themes, and Challenges (Book Review)

by adam on November 17, 2014

Simson Garfinkel and Heather Lipford’s Usable Security: History, Themes, and Challenges should be on the shelf of anyone who is developing software that asks people to make decisions about computer security.

We have to ask people to make decisions because they have information that the computer doesn’t. My favorite example is the Windows “new network” dialog, which asks what sort of network you’re connecting, home or coffee shop. The information is used to configure the firewall. My least favorite example is phishing, where people are asked to make decisions about technical minutiae before authenticating. Regardless, we are not going to entirely remove the need for people to make decisions about computer security. So we can either learn to gain their participation in more effective ways, or we can accept a very high failure rate. The former option is better, and this book is a substantial contribution.

It’s common for designers to throw up their hands at these challenges, saying things like “given a choice between security and dancing babies, people will choose dancing babies every time,” or “you can’t patch human stupidity.” However, in a recently published study by Google and UCSD, they found that the best sites only fooled 45% of the people who clicked through, while overall only 13% did. (There’s a good summary of that study available.) Claiming that “people will choose dancing babies 13% of the time” just doesn’t seem like a compelling argument against trying.

This slim book is a review of the academic work that’s been published, almost entirely in the last 20 years, on how people interact with information security systems. It summarizes and contextualizes the many things we’ve learned, mistakes that have been made, and does so in a readable and concise way. The book has six chapters:

  • Intro
  • A brief history
  • Major Themes in UPS Academic Research
  • Lessons Learned
  • Research Challenges
  • Conclusion/The Next Ten Years

The “Major themes” chapter is 61 or so pages, which is over half of the 108 pages of content. (The book also has 40 pages of bibliography). Major themes include authentication, email security and PKI, anti-phishing, storage, device pairing, web privacy, policy specification, mobile, social media and security administration.

The “Lessons Learned” chapter is quite solid, covering “reduce decisions,” “safe and secure defaults,” “provide users with better information, not more information,” “users require clear context to make good decisions,” “information presentation is critical” and “education works but has limits.” I have a quibble, which is Sasse’s concept of mental ‘compliance budgets’ is also important, and I wish it were given greater prominence. (My other quibble is more of a pet peeve: the term “user” where “people” would serve. Isn’t it nicer to say “people require clear context to make good decisions”?) Neither quibble should take away from my key message, which is that this is an important new book.

The slim nature of the book is, I believe, an excellent usability property. The authors present what’s been done, lessons that they feel can be taken away, and move to the next topic. This lets you the reader design, build or deploy systems which help the person behind the keyboard make the decisions they want to make. To re-iterate, anyone building software that asks people to make decisions should read the lessons contained within.

Disclaimer: I was paid to review a draft of this book, and my name is mentioned kindly in the acknowledgements. I am not being paid to write or post reviews.

[Updated to correct the sentence about the last 20 years.]

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