27-01-2012, 03:00 PM
Cryptography and Network Security Intro., Conventional
[attachment=16719]
Introduction
The art of war teaches us not on the likelihood
of the enemy’s not coming, but on our own
readiness to receive him; not on the chance of
his not attacking, but rather on the fact that
we have made our position unassailable.
Attacks, Services and Mechanisms
Security Attacks
Action compromises the information security
Security Services
Enhances the security of data processing and
transferring
Security mechanism
Detect, prevent and recover from a security
attack
Cryptography
Cryptography is the study of
Secret (crypto-) writing (-graphy)
Concerned with developing algorithms:
Conceal the context of some message from all except
the sender and recipient (privacy or secrecy), and/or
Verify the correctness of a message to the recipient
(authentication)
Form the basis of many technological solutions to
computer and communications security problems
History
Ancient ciphers
Have a history of at least 4000 years
Ancient Egyptians enciphered some of their
hieroglyphic writing on monuments
Ancient Hebrews enciphered certain words in the
scriptures
2000 years ago Julius Caesar used a simple substitution
cipher, now known as the Caesar cipher
Roger bacon described several methods in 1200s
[attachment=16719]
Introduction
The art of war teaches us not on the likelihood
of the enemy’s not coming, but on our own
readiness to receive him; not on the chance of
his not attacking, but rather on the fact that
we have made our position unassailable.
Attacks, Services and Mechanisms
Security Attacks
Action compromises the information security
Security Services
Enhances the security of data processing and
transferring
Security mechanism
Detect, prevent and recover from a security
attack
Cryptography
Cryptography is the study of
Secret (crypto-) writing (-graphy)
Concerned with developing algorithms:
Conceal the context of some message from all except
the sender and recipient (privacy or secrecy), and/or
Verify the correctness of a message to the recipient
(authentication)
Form the basis of many technological solutions to
computer and communications security problems
History
Ancient ciphers
Have a history of at least 4000 years
Ancient Egyptians enciphered some of their
hieroglyphic writing on monuments
Ancient Hebrews enciphered certain words in the
scriptures
2000 years ago Julius Caesar used a simple substitution
cipher, now known as the Caesar cipher
Roger bacon described several methods in 1200s
