3.1.11 Network Security Methods Notes

Network Security Methods

1. Network security is essential for protecting data, ensuring privacy, and maintaining the integrity of communication systems.
2. As networks grow more complex, the risks of attacks increase, and so do the methods used to defend against them.

Here are examples of a few widely used techniques for the defence.

Encryption

Encryption works by transforming readable data (plaintext) into an unreadable code (ciphertext) using a mathematical algorithm and a key.`

It can be of two types.

Symmetrical:

1. Uses the same key for both encryption and decryption.
2. Examples: AES (Advanced Encryption Standard), DES (Data Encryption Standard).
3. Advantages:
   1. Fast and efficient, especially for large amounts of data.
   2. Requires less computational power than asymmetric encryption.
4. Disadvantages
   1. Key distribution problem: How can two parties securely share the key?
   2. Scalability: More users = more keys to manage.

And asymmetrical (public key):

1. Uses a pair of keys: a public key for encryption and a private key for decryption.
2. Examples: RSA (Rivest-Shamir-Adleman), ECC (Elliptic Curve Cryptography).
3. Advantages:
   1. Secure key exchange — no need to share secret keys.
   2. Easier to scale for large networks.
4. Disadvantages:
   1. Slower than symmetric encryption.
   2. Requires key verification to prevent man-in-the-middle attacks.

Authentication and Access Control

OWASP Top 10 declares that the top vulnerability found in 94% cases is broken access control.

Hence, it is essential to understand what policies we can introduce to fix the issue:

1. User IDs
   1. Each user has a unique identifier.
   2. Used with passwords or multi-factor authentication (MFA).
   3. Ensures only authorised individuals have access to resources.
2. Trusted Media Access Control (MAC) Addresses
   1. Each device has a unique hardware identifier.
   2. Networks can restrict access to specific MAC addresses.
   3. Such methods are simple to implement in small networks, but are vulnerable to spoofing, where attackers fake a MAC address.
3. Although simple to implement in small networks, it becomes challenging to manage on large networks.
4. Such countermeasures are vulnerable to spoofing, where attackers fake a MAC address.