Security Attacks: Cryptography

Attacks can be of two types.

1. Active attacks :

           - Attempts to change and modify the information.
           - Easy to detect.
    
     2.  Passive attacks :

            - Attempts to obtain the information and not to modify.
            - Difficult to detect.

Passive Attacks

1. Release of Message Content.
      - Transmitted data may contain confidential information.
      - Monitors / listens the information.

2. Traffic Analysis.
       - Monitoring and observing the pattern of data transmission.


Active Attacks

1. Masquerade
         - One entity pretends to be a different entity.

2. Replay 
       - Passive capture of a data unit.
       - And it is retransmitted later.

3. Modification of Message

• A legitimate message is altered.
• And then it is retransmitted later.

4. Denial of Service.

• Break down a communication system or network.
• And making it unavailable to its intended users.