Your browser doesn't support the features required by impress.js, so you are presented with a simplified version of this presentation.

For the best experience please use the latest Chrome, Safari or Firefox browser.

CIS 115

Lecture 11: Cryptography

Message to the Class

TSTEPHAAXLISLAESCEMQIYQ

Scytale

Image Source: Wikipedia

Message to the Class

TSTEPHAAXLISLAESCEMQIYQ
T    H    I    S    I
 S    A    S    C    Y
  T    A    L    E    Q
   E    X    A    M
    P    L    E    Q

Early Ciphers

Tabula Recta

Image Source: Wikipedia

Image Source: Wikipedia


Enigma Machine

Image Source: Wikipedia

Enigma Machine Rotors

Image Source: Wikipedia

Enigma Machine Rotors

Image Source: Wikipedia

Enigma Machine Ratchet

Image Source: Wikipedia

Image Source: Wikipedia

Enigma Machine Plugboard

Image Source: Wikipedia

Enigma Key

Enigma Operation

Enigma Stengths

Enigma Weaknesses

Marian Rejewski

Image Source: Wikipedia

Cracking Enigma

Bombe

Image Source: Wikipedia

Impact

“My own conclusion is that it shortened the war by not less than two years and probably by four years … we wouldn't in fact have been able to do the Normandy Landings, even if we had left the Mediterranean aside, until at the earliest 1946, probably a bit later.”

-Sir Harry Hinsley
British Intelligence Historian

Claude Shannon

Image Source: Wikipedia

Symmetric Key Encryption

Image Source: Wikipedia

Public Key Encryption

Image Source: Askamathematician.com

RSA Encryption

RSA Example

RSA Example

RSA Keys

Assignments

Blog 5: Making Meaning - POTS

Now that we’ve finished reading the first textbook, it is time to step back and think about what we read. Write about your reactions to it and what you learned from it. I’d recommend almost treating this like an in-depth book review for others who are interested in reading the book, but don’t mind some spoilers. Some questions I’d like you to answer: