Networking

Computer Networks Prof. Hema A Murthy




Network Security

Security


Crytographic algorithms Security Services



Secret key Public key Message digest privacy authenticity Message
(DES) (RSA) (MD5) integrity




Indian Institute of Technology Madras

,Computer Networks Prof. Hema A Murthy




Secret Key Encryption

Plain text Plain text



Encrypt using Decrypt using
secret key secret key




Indian Institute of Technology Madras

,Computer Networks Prof. Hema A Murthy




Public Key Encryption
• Each participant has a secret key (private
key)
• The key is not stored
– Publish on the web (for instance)
• To send a message
– Encrypt with public key
– To decrypt, decrypt using a private key


Indian Institute of Technology Madras