Course Administration Outline of Today s lecture

Course Administration

Outline of Today’s lecture

Cryptographic Hash Functions

Some Applications of Hash Functions

Hash Output Length

Birthday Paradox

Generic Hash Function – Merkle -Damgard Construction

An Illustrative Example

Practical Examples

Further Reading

Message Authentication Codes

MAC – Functions

Security Notion for MAC

MAC Based on Block Cipher in the CBC mode – CBC-MAC

CBC-MAC

HMAC: MAC using Hash Functions

HMAC

Security of HMAC

Further Reading

Email Security

Email Security Enhancements

Pretty Good Privacy (PGP)

PGP Operation – Authentication

PGP Operation – Confidentiality

PGP Operation – Compression

PGP Operation – Summary

PGP Session Keys

PGP Public & Private Keys

PGP Key Rings

PGP Message Generation

PGP Message Reception

PGP Key Distribution

PGP Key Distribution

PGP Key Distribution Issues

PGP in Practice

References

Key Distribution

“Private Key” Distribution: An Attempt

Some questions

Key Distribution

Public Key Distribution

Naming and Certificates

Types of Certificates

Public Key Certificate

Public Key Certificate

Certificate Verification/Validation

Certificate Revocation

X. 509

X. 509 Certificate

Advantages of CA Over KDC

Public-key Infrastructure (PKI)

Problems with PKI – Private Key

Problems with PKI - Conflicts

Trustworthiness of Issuer

Further Reading

Further Reading

Some questions

Some Questions