'Polyalphabetic substitution' diaporamas de présentation

??? (Cryptology)

??? (Cryptology). ??. ???. ??. Bob. Alice. ???. 1st. 16th. ???? ?? ??. 0699 0043 1313 9642. Select odd numbers. 0 6 9 9 0 0 4 3 1 3 1 3 9 6 4 2. Select even numbers After * 2, if ? 9 then -9. 0 6 9 9 0 0 8 3 2 3 2 3 9 6 8 2. *10. 0+6+9+9+0+0+8+3+2+3+2+3+9+6+8+2 = 70.

975 views • 72 slides

CIS 628 Intro to Crypto

CIS 628 Intro to Crypto . Dr. Leonard Popyack Fall 2007. Polyalphabetic Substitution Ciphers. Flattens the frequency distribution of the ciphertext. Many ways to do this: Map high distribution plain text to multiple low distribution ciphertext.

360 views • 22 slides

Monoalphabetic and Polyalphabetic Ciphers

Monoalphabetic and Polyalphabetic Ciphers. Monoalphabetic - only one substitution/ transposition is used Polyalphabetic - where several substitutions/ transpositions are used Several such ciphers may be concatenated together to form a Product Cipher.

1.12k views • 8 slides

Monoalphabetic and Polyalphabetic Ciphers

Monoalphabetic and Polyalphabetic Ciphers. Monoalphabetic - only one substitution/ transposition is used Polyalphabetic - where several substitutions/ transpositions are used Several such ciphers may be concatenated together to form a Product Cipher.

312 views • 8 slides

336 views • 6 slides