Network Security - Security Associations (SA)

Security Association is a logical agreement between two network entities that defines how they will secure communication.

What it contains

An SA specifies:

• Encryption algorithm (AES, DES, etc.)

• Authentication method

• Cryptographic keys

• Lifetime of keys

• Mode of operation

Where it is used

• IPsec (Internet Protocol Security)

• Secure tunnels between networks

Why it is important

Without Security Associations:

• Devices won’t know how to encrypt/decrypt data

• Secure communication would fail

Simple analogy

Think of SA as a contract that says:

“We will talk using this encryption, this key, and this authentication method.”