1. SECURITY ENGINEERING 2 April 2013 William W. McMillan

2. What are the main reinforcements for breaking into software systems? Name three distinct populations of people who do this.

3. Ways People Use the Term “Risk”  Something bad that could happen:  “There’s a risk of brake failure.”  The probability that something bad could happen:  “The risk of brake failure is 0.01%.”  The cost of something bad happening:  “If the brakes fail, we risk passenger deaths.”  We can’t really regulate everyday language.

4. Ways to Mitigate Risk  Identify vulnerabilities, threats, and hazards…  …then head each one off at the pass.  Establish engineering practices that will lead to reliable software.  The first approach by itself can’t keep the bad guys out.  You can’t find every vulnerability or anticipate every attack.

5. List three to five typical kinds of attacks on software.

6. Ways to Attack abc123 Using Users Surprise Packages Picking Locks Faking/Stealing Credentials Stealing Data Observing Behavior Ganging Up As a Customer By Insider

7. What Can Be Attacked  Operating system  Databases  Financial records  Infrastructure  Communications  Dedicated servers  Application code  Application data

8. Describe a recent successful attack on a software system.

9. User Authentication  Who has access to what?  Security policy is defined by client or management.  Need to ensure that you give users the right level of access.  Operational concern.  But there are some design implications.  UI should not lead someone to, e.g., accidentally give a new engineer access to the firm’s personnel records.  Email or other communication to user to report transaction, password change, etc.

10. User Credentials  User name and password  Making 3M rich (they make Post-it Notes)…  … which is where many passwords live.  Physical cards or other object to plug into computer  Security questions  How hard is it to get people’s mother’s maiden name?  Does a friend know what the model of your first car was?  Biometrics  Retinal scans, fingerprints, voice,…

11. Is it a good idea to require users to change passwords every six months or so? Should passwords be required to be like this: fH7*iM(sqjX ?

12. Data Protection  Encryption  Fire walls  Multiple sites  In case someone corrupts databases at one site.  Checksums, consistency, or other integrity tests  Monitoring of access and traffic  User authentication  Validation of inputs  Providing read-only access when you can.

13. Is the client-server model good for protecting data in an organization?

14. Function Protection  Scan for viruses and worms.  Monitor activity.  Prevent “backdoors” and “hooks” in code.  Engineering process issue  Beware of reused software.  “You don’t know where that thing has been…”  Configure carefully when install or change.  Can change access or visibility.

15. A small dental practice has a home- grown information system and they’ve hired you to improve its security. What six or so steps would you take before making changes?