{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Understanding_Cryptography_Chptr_3---DES

Understanding_Cryptography_Chptr_3---DES - Understanding...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Understanding Cryptography – A Textbook for Students and Practitioners by Christof Paar and Jan Pelzl www.crypto-textbook.com Chapter 3 – The Data Encryption Standard (DES) ver. Nov 26, 2010 These slides were prepared by Markus Kasper, Christof Paar and Jan Pelzl
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl Some legal stuff (sorry): Terms of Use The slides can used free of charge. All copyrights for the slides remain with the authors. The title of the accompanying book “Understanding Cryptography” by Springer and the author’s names must remain on each slide. If the slides are modified, appropriate credits to the book authors and the book title must remain within the slides. It is not permitted to reproduce parts or all of the slides in printed form whatsoever without written consent by the authors.
Image of page 2
3/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl Content of this Chapter Introduction to DES Overview of the DES Algorithm Internal Structure of DES Decryption Security of DES
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl Content of this Chapter Introduction to DES Overview of the DES Algorithm Internal Structure of DES Decryption Security of DES
Image of page 4
5/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl UIstop Classification of DES in the Field of Cryptology Cryptology Cryptography Cryptanalysis Symmetric Ciphers Asymmetric Ciphers Protocols Block Ciphers Stream Ciphers You are here!
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl UIstop DES Facts Data Encryption Standard (DES) encrypts blocks of size 64 bit . Developed by IBM based on the cipher Lucifer under influence of the National Security Agency (NSA), the design criteria for DES have not been published Standardized 1977 by the National Bureau of Standards (NBS) today called National Institute of Standards and Technology (NIST) Most popular block cipher for most of the last 30 years. By far best studied symmetric algorithm. Nowadays considered insecure due to the small key length of 56 bit. But: 3DES yields very secure cipher , still widely used today. Replaced by the Advanced Encryption Standard ( AES ) in 2000 For a more detailed history see Chapter 3.1 in Understanding Cryptography
Image of page 6
7/29 Chapter 3 of Understanding Cryptography by Christof Paar and Jan Pelzl UIstop Block Cipher Primitives: Confusion and Diffusion Claude Shannon: There are two primitive operations with which strong encryption algorithms can be built: 1. Confusion: An encryption operation where the relationship between key and ciphertext is obscured . Today, a common element for achieving confusion is substitution , which is found in both AES and DES.
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern