1. Usable security + Visual design
ECE 695
Alexander J. Quinn
4/6/2016

2. Usable security – finish up
Today
Usable security – finish up
Examples of poor usability  poor security
Passwords
More tips
Visual design
Font metrics
Gestalt
Discuss

3. Usable security failures
If the 3rd to last digit of your PUID or SSN is…
ODD  think of the worst instance of unusable security you’ve ever seen.
EVEN  think of one that is fake, but might sound real. Try to fool people.
Give a 30- to 60-second rant on why it is bad.
We’ll vote and see how well we can guess.

4. Passwords

5. What matters?
Benefit Cost Entropy Cost What is cost? keystrokes? mental “chunks”?

6. What do you think?
Fingerprints
Face recognition
Voice
Retina
SecureID
Two-factor

7. Multiple lines of defense Limit cognitive/memory demands
More guidelines
Usability overall
Security overall
Multiple lines of defense
Limit cognitive/memory demands
Present syntactic information in ways attackers can’t manipulate
Expose potential anomalies
Avoid false senses of security
Consistency

8. Visual design

9. Font metrics
Credit: Ivo Vynckier,

10. Typography in CSS font-family font-size font-weight font-style
font-variant
font
letter-spacing
word-spacing
line-height
text-align
text-decoration
text-indent
text-transform
text-shadow
vertical-align
white-space
direction
unicode-bidi

11. Typography in CSS em ex ch rem Relative to viewport vh vw vmin vmax
Relative to text em ex ch
rem
Relative to viewport vh vw
vmin
vmax
Absolute px mm cm in pt pc
mozmm

12. 20 Examples of Beautiful CSS Typography Design
20 Examples of Beautiful CSS Typography Design

13. Gestalt: Similarity

14. Gestalt: Reification

15. Gestalt: Multistability

16. Gestalt: Invariance

17. Gestalt: Closure