Page 262 - CISSO_Prep_ Guide
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issuing CA ID, subject ID, and digital
signature.
Public Key Infrastructure (PKI)
• Provides the foundation for secure e-
business.
• A method for distributing trusted keys.
• Provides confidentiality, access control,
integrity, authentication, non-repudiation.
• Public keys published as certificates.
Key Management
• The key-encrypting keys must be separate
from the data keys.
• Key escrow: the third party holds on to keys.
• Key distribution center (KDC):
• End-to-end encryption
• Each user gets a key
Cryptanalysis and Attacks
• Ciphertext only attack:
• You have a sample of ciphertext only.
• Hardest.
• The object is to crack one message.
• Known plaintext attack:
• You have ciphertext & corresponding
plaintext.
• Object is to get the key.
• Chosen plaintext attack:
