One specific approach to improving the usability of systems is to reduce the burden on the end user through automation. People may be more satisfied with systems when they have more control; but in the context of security, it may be that the more control allowed the user, the greater the opportunities for introducing vulnerabilities or security breaches. To what extent and when should usable security aim to automate security decision making and remove the human from the loop entirely, versus providing a more usable interface for the human to interact with? Despite the appeal of taking the human out of the loop, participants cautioned that there are limits, because automation cannot handle unexpected, novel events—and the one thing that is known about such events is that they are certain to occur at some point.

Several specific ideas were proposed. One was to use machine learning from context to come up with an acceptable security policy for a user without the user’s directly having to adjust security or privacy parameters. Another idea was to have a user establish policy by specifying desired outcomes and having the system express those outcomes as a set of security rules. The system would then verify that the rules derived from those outcomes are consistent and complete, and only ask the user for additional instructions in the event that they are not. Research could help shed light on the feasibility of such approaches.

Authentication Beyond Passwords

Many participants noted the well-known shortcomings of passwords with respect to security and usability. Simply, the effort spent entering passwords and recovering or resetting them when they are forgotten was noted to be a significant waste of time. Passwords that are easy to remember are also easy to guess, but passwords that are hard to remember are more easily forgotten or subject to compromise if they are written. Systems often require users to change passwords periodically, which may also lead to users’ writing them down or using guessable mnemonic schemes for generating their passwords. Systems typically require their own passwords, often with conflicting rules about acceptable user names and passwords, meaning that users must keep track of a wide array of credentials.

Alternatives that address these shortcomings have been developed. They are used for certain applications but have not enjoyed widespread support and use. These alternatives include hardware token authentica-

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