Network Security Introduction
Types of Attacks
There are two general classes of network attacks:
-
Passive Attack
Hard to detect.
- Eavesdropping - Packet sniffing.
- Impersonation - Spoofing source addresses.
-
Active Attacks
- Man-in-the-Middle Attacks - Actively changing messages on the connection.
- Hijacking - Taking over an existing connection.
- Denial of Service - Overloading resources.
Types of Network Security
- Confidentiality through encryption.
- Authentication
- Message Integrity
- Access & Availability
Cryptography Notation
graph LR
Alice -->|plaintext| ea[Encryption Algorithm]
ka[KA Alice's Encryption Key] -->|kA| ea
ea -->|"ciphertext (only publicly visible part)"| da[Decryption Algorithm]
kb[Bob's Decryption Key] -->|kB| da
da -->|plaintext| Bob
In this system we use the following notation:
- $m$ - Plaintext Message.
-
$K_A(m)$ - Ciphertext, encrypted with $K_A$
\[m=K_B(K_A(m))\]