Wiretapping and Encryption

1. Wiretapping and Encryption More Week 5 cont.

2. Early Forms of Wiretapping • Party Lines • Human Operators

3. Wiretapping Today • Federal and state law enforcement • Businesses • Private Detectives • Political Candidates • ......

4. Cellular Phones • Can be tapped with over-the-counter devices

5. Standard Phones • Easily tapped if signal travels by microwave or satellite • Government has secured phones

6. Legal Mandates • 1937 - Supreme Court rules that wiretapping is illegal • 1968 - Congress explicitly allowed it by law enforcement agencies • needs court order • Electronic Communications Privacy Act include new technologies

7. Cryptography - Making and breaking of ciphers • Translation of the original message into a new incomprehensible one by a mathematical algorithm using a specific KEY • Plaintext - a message or data • Ciphertext - coded text • Decryption - decoding back to plaintext

8. Encryption Includes: • Coding scheme or cryptographic algorithm • Specific sequence of characters key used by the algorithm

9. Examples • Cereal box codes • Substitute cipher • Cryptoquip in newspaper

10. Variations - Symmetric • Use the same key to encrypt and decrypt (secret key) • Requires a more secure system to send the key than the system itself

11. Variation - Asymmetric • Use a key (public key) to encrypt a message • Another (private key) to decrypt it • Requires both keys

12. Who Uses Encryption? • Banks • Industry • Professionals • National ID cards • Criminals • .....

13. Industrial Espionage • Knowledge of a company’s cost and price structure • Market research • Strategic plans • Order and customer lists • Insider information

14. Professionals • Cellular telephones and electronic mail • unencrypted data on machines

15. Criminals • Cryptography allows criminals to keep their identities a secret • Provides security to law breakers • Allows anonymity • Don’t use systems that leave trails

16. Reliability • The longer the key has remained unbroken, the stronger it is likely to be • The longer the key is in use, the more likely someone will be able to discover it • larger amount of info will be compromised • change key frequently

17. Algorithms available • DES - Data Encryption Standard • Developed by IBM • Adopted as a Federal Information Processing Standard • Uses a 56 bit key • Has been broken • To extend life - extend key to 128 bits • or triple DES

18. RSA algorithm • Used in public key cryptography • Patented in US • Based on multiplication of large prime numbers

19. PGP - Pretty Good Privacy • Based on RSA • Used for protecting E-Mail

20. New Controversies • 1991 - Senate Bill - Government wants to be able to intercept any message and be able to decode it as well - not passed • FBI and wiretapping - Telephony bills • FBI and Clipper Chip

21. Benefits of Government Intervention • Aid law enforcement in protecting us from criminals and terrorists

22. Problems • Threats to • privacy • global competitiveness • civil liberties

23. Communications Assistance for Law Enforcement Act 1994 • to and from Requires that telecommunications equipment be designed so govt. can: • intercept all wire and electronic communic. • Intercept commun. from mobile users • Obtain call-identifying info • phone numbers • Have info transmitted to a specific location • Government will help foot the bill

24. Arguments for... • Protection from terrorists and criminals • FBI wants no new privileges • BUT • Necessity has not been justified • Expense and other problems outweigh the benefits • There has never been a guarantee of interception of private messages before

25. NEED? • Wiretaps are less useful than informants, witnesses, etc. • BUT • 90% of terrorist cases used wiretaps • Industry claims full compliance with FBI • BUT • Continued cooperation is not guaranteed

26. COST? • A lot more than government is giving • Will save money in • fines, forfeitures, prevented economic loss • Used only in a subset of investigations • Could use the money on other technologies

27. Innovation and global competitiveness • Stifle or delay new technologies • economic costs • prevent new technologies’ implementation • Damage to US competitiveness in global markets due to reduced security and privacy

28. Protection from Dossier Society • Digital cash made possible by public key encryption • Secure financial transactions without a credit card or checking account number

29. E-Cash • No link between payer and recipient • Convenience of credit card • Anonymity of cash • Use on Internet for ordinary shopping • Can transfer credentials • Can prevent duplicate cash files • Back up at home incase card is lost or stolen

30. E-Cash continued • Not easy to form a consumer profile or dossier • Prevent fraud and forgery • Protect privacy from mailing lists • More control over personal information

31. History of Encryption • Secret - NSA • National Security Agency • can do anything • has powerful computers - break ciphers and create ciphers • monitors all communications between US and other countries

32. Government Interception • NSA censored research • controlled researchers • Export restrictions • munitions • can’t export secure systems

33. Clipper Chip • Why? • need for strong encryption for business • Desire for privacy of many Americans • Provide a government back door • What? • Skipjack algorithm • Telephones and computer • field ID to tell government the key