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CIS 115

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 9: Privacy in an Open Digital World

Privacy has become a major topic of conversation in technology over the past decade. Between the push for ever-tighter security after the attacks on September 11th, 2001, and the revelations from Edward Snowden (and others) that massive amounts of data about ordinary people is being collected and analyzed each day, it is a topic that affects each and every one of us.

Many news outlets use the term "pendulum" when talking about the balance between security and privacy, since public opinion seems to swing back and forth between the two depending on recent events and personal beliefs. (Just search for "privacy pendulum" online to see what I mean.)

For this blog article, right about your personal viewpoint regarding security vs. privacy on the internet. For example: