Block Ciphers and the Data Encryption

Goals:

• To introduce the notion of a block cipher in the modern context.
• To talk about the infeasibility of ideal block ciphers
• To introduce the notion of the Feistel Cipher Structure
• To go over DES, the Data Encryption Standard
• To illustrate some of the DES steps with Python code

contents

• Ideal Block Cipher
• The Feistel Structure for Block Ciphers
• DES: The Data Encryption Standard
• What Makes DES a Strong Cipher (to the 41 Extent It is a Strong Cipher)