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Wiretapping and Encryption

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E-Cash. No link between payer and recipient. Convenience of ... E-Cash continued. Not easy to form a consumer profile or dossier. Prevent fraud and forgery ... – PowerPoint PPT presentation

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Title: Wiretapping and Encryption


1
Wiretapping and Encryption
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 secret codes
  • 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 companys 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
National ID Cards
  • Strong encryption can be used to authenticate
    data - unforgeable
  • Users would have to have a reader with the
    governments public key to decrypt
  • Fearful of key leakage
  • Accessibility to law enforcement agencies

16
Criminals
  • Cryptography allows criminals to keep their
    identities a secret
  • Provides security to law breakers
  • Allows anonymity
  • Dont use systems that leave trails

17
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

18
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

19
RSA algorithm
  • Used in public key cryptography
  • Patented in US
  • Based on multiplication of large prime numbers

20
PGP - Pretty Good Privacy
  • Based on RSA
  • Used for protecting E-Mail

21
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

22
Benefits of Government Intervention
  • Aid law enforcement in protecting us from
    criminals and terrorists

23
Problems
  • Threats to
  • privacy
  • global competitiveness
  • civil liberties

24
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

25
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

26
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

27
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

28
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

29
Public Key Cryptography
  • Public Keys
  • Secret key for each pair of parties who wish to
    communicate privately
  • key is passed between the parties in a method
    more secure than the method used for sending the
    messages

30
HISTORY
  • 1970 - Developed by Diffie Hellman
  • Two mathematically related keys
  • to encrypt
  • to decrypt
  • Knowing the key to encrypt does not help decrypt
  • Each person has their own key pair

31
History
  • The encrypting key can become public
  • Public key - encrypt
  • Private key - decrypt
  • Senders can ID the recipients public key to
    encrypt yet only the recipient can decrypt it.
  • No need to transfer secret keys

32
Digital Signature
  • Add a statement of acceptance to the electronic
    document
  • encrypted with private key
  • cyphertext is decrypted with public key
  • providing any other key produced gibberish
  • Others can decrypt and read but only the one with
    the right key is signed

33
Protection from Dossier Society
  • Digital cash made possible by public key
    encryption
  • Secure financial transactions without a credit
    card or checking account number

34
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

35
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

36
History of Encryption
  • Secret - NSA
  • National Security Agency
  • can do anything
  • has powerful computers - break cyphers
  • monitors all communications between US and other
    countries and within
  • Designs and breaks cyphers

37
Government Interception
  • NSA censored research
  • controlled researchers
  • DES thought to have back door
  • Export restrictions
  • munitions
  • cant export secure systems

38
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

39
Arguments - government side
  • Protect us from bad guys
  • provide better encryption for everyone
  • ensure needs of law enforcement and national
    security are met
  • improve privacy

40
Other Side
  • Criminals can encrypt themselves before putting
    through NSA chips
  • Global trade opportunities reduced
  • Free market will develop better products than the
    government
  • Security risks of government key escrow
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