(updated on April 18)

Note 1: Danger of open network communication such as Internet

Note 2: Symmetric Key Crypto-System

Note 3: Problem with Symmetric Key Crypto-System

Note 4: Data Encryption using a Public Key Crypto-System

Note 5: Key Management problem for Public Key crypto-System

Note 6: Digital signature using Public Key Crypto-System

Note 7: Problem with wrong public key

Note 8: Certification Authority vs key server

Note 9: Why strong cryptography is needed?

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