July 22, 2009…
At the end of the lecture…
Something we learnt today…
At the end of the lecture…
Something we learnt today…
Steganography - art of hide something…
- eg: Hide information inside a picture…
- eg: Hide information inside a picture…
Cryptography - art of secret writing…
- eg: Replacing the actual word with any other word…
- use symmetric & asymmetric key…
- Symmetric – 1 key use 2 encrypt and decrypt code…
- Asymmetric (public key ops.) – 1 key use 2 encrypt, 1 key use 2 decrypt…
- Does involve key – plaintext (original msg.), key, ciphertext (coded msg)…
- Type of operation: i. Substitution
ii. Transposition
iii. Product
- Way of transforming cryptography:
i. Block
ii. Stream
ii. Stream