Unit 5: Network Security Model

Network Security Model


1- Design an algorithm to performing the security related transformation
2- Generate the secret information to be used with the algorithm
3- Develop methods for the distribution and sharing of the secret information
4- Secret information to achieve a particular security task



- Plain TextP: The original Message
- Cipher Text: The coded message ( with key )
- Cipher: Algorithm for transforming plain text to cipher text
- Key: Info used in cipher known only to sender and receiver
- Encrypt: Converting plain text to cipher text
- Decrypt: Recover plain text from cipher text



Stream Cipher
- Operates on small Units of Plain Text
- Faster operation
- Stream cipher processes the input element continuously producing output one element at a time.
- Need less code
- Only one time of key used

Block Cipher
- Operates on larger block of data
- Slower operation
- Block cipher processes the input one block at a time producing an output block for each input block.
- Need more code
- Key reuse is possible

Who is he ?