1. Security Grant Hutchins CS Discussion Group Tuesday, October 22, 2002

2. Overview Encryption Viruses / Worms / Other Bad Stuff

3. Encryption – History Caesar Cipher Enigma RSA Quantum Cryptography WEP

4. Caesar Cipher Simple Quick Easy to Break A becomes B, B becomes C, C becomes D, etc. GRANT HUTCHINS - HSBOUIVUDIJOT OLIN - PMJO

5. Enigma Nazi Germany – World War II Mechanical Requires complex machine Broken by British scientists

6. RSA 1977 Ron Rivest, Adi Shamir, Leonard Adleman Requires large calculations Simple algorithm dealing with large primes Allows for public- and private-key cryptography Breakable with incredibly large amounts of computations

7. RSA – How it’s used Alice tells Bob her public key Bob uses this public key to encrypt a message Alice receives this message across an insecure channel Only Alice can decode it, using her private key (which she has password-protected on her computer)

8. Quantum Cryptography 1960 – Stephen Wiesner’s “quantum money” Uses single-photon pulses down a fiber- optic line Expensive to set up, requires direct fiber- optic connection Impossible to break (unless you disobey the laws of Quantum Physics)

9. Quantum Cryptography – How it works Alice sends Bob a photon polarized in some direction (vertical, horizontal, slash, or backslash) Bob measures these with either a horizontal-vertical filter or a slash- backslash filter H-V filter gives ambiguous results on slash or backslash, and vice versa

10. Quantum Encryption – How it works Bob tells Alice in which order he used which filters, and Alice tells him which of his filters were correct. Alice and Bob throw away the ambiguous results and compare a small portion of what’s left to see if it matches Everything else is their key

11. Quantum Encryption – How it works Eve breaks in! She intercepts the photons and measures them herself. Whenever she uses the wrong filter, she changes the polarization of the photon. Alice and Bob don’t get the same results and know they’re being spied on Eve goes away and cries

12. WEP Wired Equivalent Privacy Used for 802.11b wireless LANs (like Olin’s) Relatively weak

13. Viruses / Worms / Other Bad Stuff Virus vs. Worm vs. Other Bad Stuff The Great Internet Worm Email Worms Adware and Spyware

14. Virus vs. Worm vs. Other Bad Stuff Virus – Code tacked onto the end of some executable that copies itself to other executables Worm – Similar to virus, but actively sends itself to other computers Malware – (includes adware and spyware) Programs installed unbeknownst to users Trojan Horses – Programs that do more than what they tell you Social Engineering – Someone who sounds important asks you for urgent information

15. The Great Internet Worm Robert T. Morris – 1988 Wrote experimental self-replicating program Spread to around 6,000 major Unix machines (significant percentage of Internet at the time) Morris claimed it was an innocent experiment that got out of hand

16. The Great Internet Worm Cost to repair: $10m - $100m Morris was convicted under the Fraud and Abuse Act (Title 18) Sentence: 3 years probation, 400 hours community service, and $10,050 fine

17. Email Worms Often exploit Outlook and Outlook Express Trick users into believing they are legitimate emails

18. Example Worm (from yesterday) From: Wilma Hardenburgh [pen@compuserve.com] Sent: Monday, October 21, 2002 5:52 PM To: undisclosed-recipients: Subject: Fw: [cyberscribes] Request for Alphabet Sentences Sally - I thought you might like to save this list of alphabet sentences to a disk. There are at least 50-70 of them on this list. Some of them a "little racy!" (see her list below.) Just thought you might be able to refer to it if you should need some new ones for your classes. They were sent to me by a Cyberscr

19. Let’s View the Source!!! Sally - I thought you might like to save this list of alphabet sentences to a disk. There are at least 50-70 of them on this list. Some of them a "little racy!" (see her list below.) Just thought you might be able to refer to it if you should need some new ones for your classes. They were sent to me by a Cyberscr

20. cid:zYkp6zI51zy2qcid:zYkp6zI51zy2q ??? Could be just about anything, unfortunately. Thanks Microsoft! http://282578851835148/

21. Spyware and Adware Installed usually without user knowledge Spyware watches what you do and where you go online and reports it to someone Adware causes ads to pop up on your screen Lavasoft Ad-Aware can get rid of most malware! http://www.lavasoftusa.comhttp://www.lavasoftusa.com

22. Other stuff worth mentioning Steganography – Disguising a message in something else such as an image PGP – “Pretty Good Privacy” – the first publicly available implementation of public- and private-key cryptography (“Cryptography for the masses”)