Más contenido relacionado


Cryptography and network security

  1. Cryptography and Network Security Dr.S.Santhi Professor Department of ECE KIT-Kalaignarkarunanidhi Institute of Technology
  2. Agenda What Is Cryptography? Types of Cryptographic Functions. Network Security Models.
  3. Cryptography • The art of secret writing. The art of mangling information into apparent unintelligibility in a manner allowing a secret method of unmangling.
  4. Cryptography Definitions • Messages: – Plaintext – Ciphertext • Ingredients: – Algorithm(s) – Key(s) • Players: – Cryptographer: invents clever algorithms – Cryptanalyst: breaks clever algorithms
  5. Basic Terminology • Plaintext: original message to be encrypted • Ciphertext: the encrypted message • Enciphering or encryption: the process of converting plaintext into ciphertext • Encryption algorithm: performs encryption • Two inputs: a plaintext and a secret key
  6. Symmetric Key Cryptography • This private/secret/single key cryptography uses one key • This key is shared by both sender and receiver • if this key is disclosed communications are compromised • It is also called symmetric, parties are equal • It does not protect sender from receiver forging a message & claiming is sent by sender
  7. Asymmetric Key Cryptography • It uses two keys – Private and Public key • Asymmetric – Both sender and receiver use different keys • It works by the clever use of number theory problems • It complements rather than replaces private key cryptography
  8. MODELS FOR NETWORK SECURITY • Model for Network Security • Network Access Security Model
  9. Model for Network Security
  10. Network Access Security Model
  11. Thank You