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Published byHoward Stewart Modified over 9 years ago
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Wiretapping and Encryption More Week 5 cont.
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Early Forms of Wiretapping uParty Lines uHuman Operators
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Wiretapping Today uFederal and state law enforcement uBusinesses uPrivate Detectives uPolitical Candidates u......
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Cellular Phones uCan be tapped with over- the-counter devices
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Standard Phones uEasily tapped if signal travels by microwave or satellite uGovernment has secured phones
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Legal Mandates u1937 - Supreme Court rules that wiretapping is illegal u1968 - Congress explicitly allowed it by law enforcement agencies u needs court order uElectronic Communications Privacy Act include new technologies
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Cryptography - Making and breaking of ciphers uTranslation of the original message into a new incomprehensible one by a mathematical algorithm using a specific KEY uPlaintext - a message or data uCiphertext - encrypted text uDecryption - decipher back to plaintext
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Encryption Includes: uCoding scheme or cryptographic algorithm uSpecific sequence of characters key used by the algorithm
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Examples uCereal box codes uSubstitute cipher uCryptoquip in newspaper
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Variations - Symmetric uUse the same key to encrypt and decrypt (secret key) uRequires a more secure system to send the key than the system itself
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Variation - Asymmetric uUse a key (public key) to encrypt a message uAnother (private key) to decrypt it uRequires both keys
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Who Uses Encryption? uBanks uIndustry uProfessionals uNational ID cards uCriminals u.....
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Industrial Espionage uKnowledge of a company’s cost and price structure uMarket research uStrategic plans uOrder and customer lists uInsider information
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Professionals uCellular telephones and electronic mail uunencrypted data on machines
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Criminals uCryptography allows criminals to keep their identities a secret uProvides security to law breakers uAllows anonymity uDon’t use systems that leave trails
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Reliability uThe longer the key has remained unbroken, the stronger it is likely to be uThe longer the key is in use, the more likely someone will be able to discover it u larger amount of info will be compromised u change key frequently
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Algorithms available uDES - Data Encryption Standard u Developed by IBM in the 1970’s u Adopted as a Federal Information Processing Standard u Uses a 56 bit key uHas been broken uTo extend life - extend key to 128 bits u or triple DES
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RSA algorithm uUsed in public key cryptography uPatented in US uBased on multiplication of large prime numbers
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PGP - Pretty Good Privacy uBased on RSA uUsed for protecting E-Mail
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New Controversies u1991 - Senate Bill - Government wants to be able to intercept any message and be able to decode it as well - not passed uFBI and wiretapping - Telephony bills uFBI and Clipper Chip
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Benefits of Government Intervention uAid law enforcement in protecting us from criminals and terrorists
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Problems uThreats to u privacy u global competitiveness u civil liberties
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Communications Assistance for Law Enforcement Act 1994 uto and from Requires that telecommunications equipment be designed so govt. can: u intercept all wire and electronic communic. u Intercept comms from mobile users u Obtain call-identifying info u phone numbers u Have info transmitted to a specific location uGovernment will help foot the bill
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Arguments for... uProtection from terrorists and criminals uFBI wants no new privileges uBUT u Necessity has not been justified u Expense and other problems outweigh the benefits u There has never been a guarantee of interception of private messages before
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NEED? uWiretaps are less useful than informants, witnesses, etc. uBUT u 90% of terrorist cases used wiretaps uIndustry claims full compliance with FBI uBUT u Continued cooperation is not guaranteed
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COST? uA lot more than government is giving uWill save money in u fines, forfeitures, prevented economic loss uUsed only in a subset of investigations uCould use the money on other technologies
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Innovation and global competitiveness uStifle or delay new technologies u economic costs u prevent new technologies’ implementation uDamage to US competitiveness in global markets due to reduced security and privacy
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Protection from Dossier Society uDigital cash made possible by public key encryption uSecure financial transactions without a credit card or checking account number
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E-Cash uNo link between payer and recipient uConvenience of credit card uAnonymity of cash uUse on Internet for ordinary shopping uCan transfer credentials uCan prevent duplicate cash files uBack up at home in case card is lost or stolen
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E-Cash continued uNot easy to form a consumer profile or dossier uPrevent fraud and forgery uProtect privacy from mailing lists uMore control over personal information
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History of Encryption uSecret - NSA uNational Security Agency u can do anything u has powerful computers - break ciphers and create ciphers u monitors all communications between US and other countries
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Government Interception uNSA censored research u controlled researchers u Export restrictions u munitions u can’t export secure systems
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