BLOCK CIPHER SYSTEMS OPERATION MODES OF DATA ENCRYPTION STANDARD (DES)

Slides:

Advertisements

Similar presentations

DES The Data Encryption Standard (DES) is a classic symmetric block cipher algorithm. DES was developed in the 1970’s as a US government standard The block.

Advertisements

Chapter 4: Modes of Operation CS 472: Fall Encrypting a Large Massage 1.Electronic Code Book (ECB) 2.Cipher Block Chaining (CBC) 3.Output Feedback.

International Data Encryption Algorithm

The Data Encryption Standard - see Susan Landau’s paper: “Standing the test of time: the data encryption standard.” DES - adopted in 1977 as a standard.

“Advanced Encryption Standard” & “Modes of Operation”

Encipherment Using Modern Symmetric-Key Ciphers. 8.2 Objectives ❏ To show how modern standard ciphers, such as DES or AES, can be used to encipher long.

Modern Symmetric-Key Ciphers

CS 483 – SD SECTION BY DR. DANIYAL ALGHAZZAWI (3) Information Security.

Symmetric Encryption Example: DES Weichao Wang. 2 Overview of the DES A block cipher: – encrypts blocks of 64 bits using a 64 bit key – outputs 64 bits.

Web Security for Network and System Administrators1 Chapter 4 Encryption.

Cryptography and Network Security Chapter 6. Chapter 6 – Block Cipher Operation Many savages at the present day regard their names as vital parts of themselves,

Cryptography1 CPSC 3730 Cryptography Chapter 6 Triple DES, Block Cipher Modes of Operation.

CMSC 414 Computer (and Network) Security Lecture 5 Jonathan Katz.

1 Lect. 9 : Mode of Operation. 2 Modes of Operation – ECB Mode  Electronic Code Book Mode Break a message into a sequence of plaintext blocks Each plaintext.

Chapter 5 Cryptography Protecting principals communication in systems.

1 Overview of the DES A block cipher: –encrypts blocks of 64 bits using a 64 bit key –outputs 64 bits of ciphertext A product cipher –basic unit is the.

Modes of Operation CS 795. Electronic Code Book (ECB) Each block of the message is encrypted with the same secret key Problems: If two identical blocks.

Introduction to Symmetric Block Cipher Jing Deng Based on Prof. Rick Han’s Lecture Slides Dr. Andreas Steffen’s Security Tutorial.

Computer Networking Lecture 21: Security and Cryptography Thanks to various folks from , semester’s past and others.

Lecture 23 Symmetric Encryption

CS470, A.SelcukModes of Operation1 Encrypting with Block Ciphers CS 470 Introduction to Applied Cryptography Instructor: Ali Aydin Selcuk.

1 Chapter 4 Encryption. 2 Objectives In this chapter, you will: Learn the basics of encryption technology Recognize popular symmetric encryption algorithms.

Block Cipher Transmission Modes CSCI 5857: Encoding and Encryption.

Modes of Operation. Topics  Overview of Modes of Operation  EBC, CBC, CFB, OFB, CTR  Notes and Remarks on each modes.

Cryptography and Network Security Chapter 6. Multiple Encryption & DES  clear a replacement for DES was needed theoretical attacks that can break it.

Chapter 20 Symmetric Encryption and Message Confidentiality.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Security PART VII.

THE FAMILY OF BLOCK CIPHERS “SD-(n,k)” S. Markovski D. Gligoroski V. Dimitrova A. Mileva.

Lecture 4: Using Block Ciphers

TE/CS 536 Network Security Spring 2006 – Lectures 6&7 Secret Key Cryptography.

Cryptography and Network Security

Block ciphers Structure of a multiround block cipher

AVALANCHE EFFECT IN THE FAMILY OF BLOCK CIPHERS “SD-(n,k)” University “Ss Cyril and Methodius” – Skopje, RM S. Markovski, PhD A. Mileva, MSc D. Gligoroski,

Multiple Encryption & DES  clearly a replacement for DES was needed Vulnerable to brute-force key search attacks Vulnerable to brute-force key search.

Chapter 9: Algorithms Types and Modes Dulal C. Kar Based on Schneier.

Encryption Types & Modes Chapter 9 Encryption Types –Stream Ciphers –Block Ciphers Encryption Modes –ECB - Electronic Codebook –CBC - Cipher Block Chaining.

More About DES Cryptography and Network Security Reference: Sec 3.1 of Stallings Text.

Data Encryption Standard (DES) © 2000 Gregory Kesden.

1.1 Chapter 8 Encipherment Using Modern Symmetric-Key Ciphers Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Introduction to Computer Security ©2004 Matt Bishop Information Security Principles Assistant Professor Dr. Sana’a Wafa Al-Sayegh 1 st Semester

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Security.

DES Algorithm Data Encryption Standard. DES Features Block cipher, 64 bits per block 64-bit key, with only 56 bits effective ECB mode and CBC mode.

Chapter 9 Encrypting Volumes. FIGURE 9.0.F01: A hard drive volume with full-disk encryption (FDE).

Modes of Usage Dan Fleck CS 469: Security Engineering These slides are modified with permission from Bill Young (Univ of Texas) 11 Coming up: Modes of.

Modes of Operation INSTRUCTOR: DANIA ALOMAR. Modes of Operation A block cipher can be used in various methods for data encryption and decryption; these.

1 Symmetric-Key Encryption CSE 5351: Introduction to Cryptography Reading assignment: Chapter 3 Read sections first (skipping 3.2.2)

Stream Ciphers and Block Ciphers A stream cipher is one that encrypts a digital data stream one bit or one byte at a time. Examples of classical stream.

Cryptography and Network Security Chapter 6 Fifth Edition by William Stallings Lecture slides by Lawrie Brown.

Lecture 23 Symmetric Encryption

1 Symmetric key cryptography: DES DES: Data Encryption Standard US encryption standard [NIST 1993] 56-bit symmetric key, 64 bit plaintext input How secure.

Privacy and Integrity: “ Two Essences of Network Security” Presenter Prosanta Gope Advisor Tzonelih Hwang Quantum Information and Network Security Lab,

Cryptography and Network Security

Cipher Transmission and Storage Modes Part 2: Stream Cipher Modes CSCI 5857: Encoding and Encryption.

@Yuan Xue 285: Network Security CS 285 Network Security Message Authentication Code Data integrity + Source authentication.

Block Cipher Modes Last Updated: Aug 25, ECB Mode Electronic Code Book Divide the plaintext into fixed-size blocks Encrypt/Decrypt each block independently.

Block Cipher Encrypting a large message Electronic Code Book (ECB) message m1 m2 m3 m4 m5 m6 c1 c2 c3 c4 c5 c6 E E E Secret.

CS480 Cryptography and Information Security

Computer and Network Security

Block Cipher Modes CS 465 Make a chart for the mode comparisons

رمزنگاري متقارن بهروز ترك‏لاداني 1.

مروري برالگوريتمهاي رمز متقارن(كليد پنهان)

Block cipher and modes of encryptions

Algorithm Types & Algorithm Modes

Symmetric-Key Encryption

Block vs Stream Ciphers

Block Ciphers: DES and AES

Encryption Basics Types of ciphers Algorithms Modes Key Length

Counter Mode, Output Feedback Mode

Elect. Codebook, Cipher Block Chaining

Presentation transcript:

BLOCK CIPHER SYSTEMS OPERATION MODES OF DATA ENCRYPTION STANDARD (DES)

DES Decryption (DES -1 ) : The same function used for encryption and decryption except if encryption keys are (K1, K2, …, K16) then the decryption keys are (K16, K15, …, K1) and in spite of cyclic shift left used in encryption the cyclic right shift is used in decryption. cyclic right shiftCyclic left shift decryption encryption

OPERATION MODES OF DES : 1- Electronic Code Book (ECB). 2- Cipher Block Chaining ( CBC). 3- Cipher Feed Back (CFB). 4- Output Feed Back (OFB).

56 bit key + 8 parity bit DES block encryption DES block decryption Data Storage Device 64 bit block of ciphertext in stage medium 64 bit block of plaintext 1- Electronic Code Book (ECB).

2- Cipher Block Chaining ( CBC).

3- Cipher Feed Back (CFB).

4- Output Feed Back (OFB).