2. What is cryptography
Cryptography is the science of information security.
The word is derived from the Greek, kryptos- hidden
Graphy-writing.
It’s a efficient method of transmitting messages in a
secured manner.
3. History of cryptography
The history of cryptography has been
explained in following slides with pictorial
representation
It is further classified into
• Ancient cryptography
• Modern cryptography
6. Ancient Cryptography
History tells us that Julius Caesar enciphered his dispatches
by writing D for A
Ex: If message is “CALL ME” means, It is encrypted to“FDOO PH“
9. Purpose of cryptography
Authentication: The process of proving one's identity.
Confidentiality: Ensuring that no one can read the
message except the intended receiver.
Integrity: Assuring the receiver that the received
message has not been altered in any way from the original.
Non-repudiation: A mechanism to prove that the
sender really sent this message
11. Terminology
Key word
The shared secret used to keep the message secret
Ciphertext
The encrypted message
Encryption
The process of turning plaintext to ciphertext
Decryption
Opposite to the Encryption
15. Hash function
Hash function also called as message digest
It doesn't require the key, since plaintext not
recovered from ciphertext.
Hash function are typically used for
verification of file content.
16. Application of cryptography
There are many applications available. Few
of them listed below.
Digital Signature
Smart card
Electronic commerce
Computer password
ATM
17. Conclusion
Cryptography is only the part of security
system
Its not a magic bullet
Even though technology improved, there is
some deflect. No one in world is perfect and
stable
we try improve our self in future needs