'Vigenere cipher' diaporamas de présentation

Cryptography

401 views • 31 slides

A Cryptography Tutorial

A Cryptography Tutorial. Jim Xu College of Computing Georgia Tech http://www.cc.gatech.edu/~jx. Why Cryptography?. Network information needs to be communicated through insecure channel. Stored information may be accessed without proper authorization.

392 views • 24 slides

Cryptography

302 views • 20 slides

Introduction to Information Security Chapter II : Classical Ciphers

Introduction to Information Security Chapter II : Classical Ciphers. Contents. History of cryptographic research Substitution ciphers Caesar ciphers Affine ciphers Monoalphabetic substitution cipher Homophonic substitution cipher Polyalphabetic substitution cipher Vigenere cipher

165 views • 16 slides

Encryption on the Internet

201 views • 12 slides

Announcements: Programming exam next Thursday on breaking codes from chapter 2

DTTF/NB479: Dszquphsbqiz Day 6. Announcements: Programming exam next Thursday on breaking codes from chapter 2 Written exam at start of week 4 on concepts from chapter 2 Questions? This week: see schedule page 2 days of chapter 3, then back to Hill cipher.

176 views • 11 slides

Section 2.6 Probability and Expectation

160 views • 8 slides

Substitution Ciphers

Substitution Ciphers. Reference Matt Bishop, Computer Security , Addison Wesley, 2003. Substitution Ciphers (p.2). Substitution Cipher Changes characters in the plaintext to produce the ciphertext. Examples Caesar Cipher Vigenere Cipher One Time Pad. Substitution Ciphers (p.3).

313 views • 5 slides

Substitution Ciphers

Substitution Ciphers. Substitute a letter with another letter Caesar Cipher Mono alphabetic Very easy to break Vigenere Cipher Poly alphabetic Took 300 years to break Kasiski Attack Now we know it is easily breakable. Vigenere Cipher Table A B C D E F G H I J K L M N O P

674 views • 2 slides