IS03-Cryptography

IS03-Cryptography - Pintu R Shah Pintu In this unit....

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
intu Shah Pintu R Shah
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
In this unit. . c Cryptography basics c Transposition ciphers c Substitution ciphers c Data Encryption Standard c Public key cryptography c Streams and block ciphers c Key Management c Digital Signature c PEM and IPSec. Pintu R Shah MPSTME SVKM's NMIMS 2
Background image of page 2
What is cryptography? c Cryptography (from Greek word kryptos meaning "hidden, secret"; and gráphō , "I write") is the practice and study of hiding information. ryptanalysis is breaking of codes c Cryptanalysis is breaking of codes Pintu R Shah MPSTME SVKM's NMIMS 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Terminologies c Plain Text: the original information. c Cipher text: unintelligible gibberish data. It is the output of encryption process c Encryption,is the process of converting ordinary information (plaintext) into unintelligible gibberish (i.e., cipher text). c Decryption is the reverse, in other words, moving from the unintelligible ciphertext back to plaintext. c A cipher (or cypher) is a pair of algorithms which create the encryption and the reversing decryption. The detailed operation of a cipher is controlled both by the algorithm and in each instance by a key. c Key:This is a secret parameter (ideally known only to the communicants) for a specific message exchange context. Pintu R Shah MPSTME SVKM's NMIMS 4
Background image of page 4
Goals of cryptography c Four primary goals c Confidentiality c Integrity c Nonrepudiation c Authentication c Many applications provide multiple cryptographic benefits simultaneously c For example: e-mail cryptography systems Pintu R Shah MPSTME SVKM's NMIMS 5
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Goals of Cryptography c Confidentiality is most commonly addressed goal c The meaning of a message is concealed by encoding it c The sender encrypt s the message using a cryptographic ey key c The recipient decrypt s the message using a cryptographic key that may or may not be the same as the one used by the sender Pintu R Shah MPSTME SVKM's NMIMS 6
Background image of page 6
Goals of Cryptography (continued) c Integrity c Ensures that the message received is the same as the message that was sent ses ash g to create a unique message digest from the c Uses hash ing to create a unique message digest from the message that is sent along with the message c Recipient uses the same technique to create a second digest from the message to compare to the original one c This technique only protects against unintentional alteration of the message c A variation is used to create digital signatures to protect against malicious alteration Pintu R Shah MPSTME SVKM's NMIMS 7
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Goals of Cryptography (continued) c Non repudiation c The sender of a message cannot later claim he/she did not send it vailable ith asymmetric cryptosystems that can create c Available with asymmetric cryptosystems that can create digital signatures Pintu R Shah MPSTME SVKM's NMIMS 8
Background image of page 8
Goals of Cryptography (continued) c Authentication c A user or system can prove their identity to another who does not have personal knowledge of their identity ccomplished sing igital certificates c Accomplished using digital certificates c Kerberos is a common cryptographic authentication system Pintu R Shah MPSTME SVKM's NMIMS 9
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/04/2011 for the course IT 100 taught by Professor Rickdas during the Spring '11 term at University of Mumbai.

Page1 / 102

IS03-Cryptography - Pintu R Shah Pintu In this unit....

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online