Cryptography
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Cryptography is the science of securing information and communication through encryption. It has a long history dating back to ancient civilizations, but modern cryptography emerged in the early 20th century with the invention of encryption machines like the Enigma and Lorenz ciphers used in World War II. Cryptography serves purposes like authentication, confidentiality, integrity, and non-repudiation. It uses techniques like symmetric encryption with a shared key, asymmetric encryption with public/private key pairs, and hash functions. Cryptography has many applications in digital signatures, smart cards, e-commerce, passwords, and ATMs. While technology has improved security, perfection has not been achieved.
Cryptography
- 1. Concept of Cryptography Presented by KuralAmuthan.C.V Nirmalkumar.R.E Ramkumar.M Manimaran.M
- 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
- 4. Ancient cryptography Sumerian’s cuneiform writing (3500 BC)
- 5. Ancient cryptography Egypt's cryptography writing(1900 BC)
- 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“
- 7. Modern cryptography “The Enigma Machine” invented by German military during world war I.
- 8. Modern cryptography German Lorenz cipher machine, used in World War II to encrypt very-high-level general staff messages
- 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
- 12. Types of Cryptography Symmetry cryptography Asymmetry cryptography Hash function
- 13. Symmetric Cryptography Uses same key for both encryption and decryption
- 14. Asymmetric Cryptography Also known as public key Uses two key (public & private) for encryption and decryption Public key Private key
- 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