10) Security

What is network security?

Protecting data and services from attacks

What is confidentiality?

Only sender and receiver understand message

What is authentication?

Verifying identity of sender or receiver

What is message integrity?

Ensuring message is not altered

What is availability?

Services remain accessible

What can attackers do?

Eavesdrop insert spoof hijack DoS

What is eavesdropping?

Intercepting messages

What is spoofing?

Faking identity

What is hijacking?

Taking over connection

What is DoS?

Overloading system to block access

What is plaintext?

Original message

What is ciphertext?

Encrypted message

What is encryption?

Converting plaintext to ciphertext

What is decryption?

Converting ciphertext to plaintext

What is symmetric key crypto?

Same key used for encryption and decryption

What is AES?

Modern symmetric encryption standard

What is public key crypto?

Uses public and private key pair

What is public key?

Known to everyone

What is private key?

Known only to owner

What is RSA?

Public key encryption algorithm

What makes RSA secure?

Hard to factor large numbers

What is session key?

Temporary symmetric key

What is digital signature?

Encrypt hash with private key

What does digital signature provide?

Authentication integrity non-repudiation

What is hash function?

Creates fixed-size message digest

What is message digest?

Fingerprint of message

What is CA?

Certifies public keys

What is certificate?

Binds identity to public key

What problem do CAs solve?

Prevent fake public keys