Basic of Elementry Cryptography. Types of cryptography & broad categorization of Encryption algorithm

1. School of Computer Science & Information Technology Presentation On Elementary Cryptography Presented by: Anshul Jain (NM) Sumit Lole (CS) M.Tech. II sem Guided by: Dr. D.S. Bhilare

13. Comparison Secret Key (Symmetric) Public Key (Asymmetric) Number of Key 1 2 Protection of Key Must be kept secret One key must be kept secret 7 other can be freely exposed Best Uses Cryptographic workhorse; secrecy and integrity of data, single characters to blocks of data, messages, files Key exchange, authentication Key Distribution Must be out-of-band Public key can be used to distribute other keys Speed Fast Slow; typically, 10,000 times slower than secret key

19. Comparison between DES & AES DES AES Date 1976 1997 Block Size 64 bits 128 bits Key Length 56 bits(effective length) 128, 192, 256 ( possibly more) bits Encryption Primitive Substitution, permutation Substitution, shift, bit mixing Cryptographic Primitive Open Open Design Close Open Selection Process Secret Secret, but accepted open public comment

25. Cont…

28. Digital Signature A digital signature is a protocol that produces the same effect as a real signature: It is a mark that only the sender can make, but other people can easily recognize as belonging to the sender. Just like a real signature, a digital signature is used to confirm agreement to a message.

30. Thank You