Page 259 - CISSO_Prep_ Guide

▪ El Gamal – like RSA but
unpatented.
▪ LUC.
• Others
▪ Merkle-Hellman Knapsack
(broken).
▪ Chor-Rivest knapsack (broken).

Hybrid Systems – PGP, S/MIME, VPN/SSL. Hybrid
systems use symmetric for bulk data encryption
and asymmetric for key distribution.

Message Integrity Controls
• Accidental change detection is done
through parity, hashing, and checksums.
• Intentional change detection is done
through digital signature, HMAC, and
CBC-MAC.
• CBC-MAC
▪ Hash the ciphertext
▪ Encrypt the ciphertext using
Cipher Block Chaining (CBC).
▪ Take the last encrypted hash
block and encrypt it again.
• Note: WPA2 the
message is considered a
“frame,” not a block
▪ That value becomes the
message authentication code