What is ECB (Electronic CodeBook) Operation Mode?

This section describes what is ECB (Electronic CodeBook) Operation Mode - each plaintext block is encrypted independently without any input from other blocks.

ECB (Electronic CodeBook) is the simplest operation mode comparing to other operation modes. It can be described by the formula and the diagram below with notations defined earlier:

C[i] = Ek(P[i])

 P[1]--|       P[2]--|       P[3]--|
       |             |             |
     Ek()          Ek()          Ek()
       |             |             | 
     C[1]          C[2]          C[3]

As you can see from the formula and the diagram, in ECB mode, each ciphertext block is obtained by applying the DES encryption process to the current plaintext block directly. So the current ciphertext block has not dependency on any previous plaintext blocks.

The disadvantage of ECB mode is that identical plaintext blocks are encrypted to identical ciphertext blocks; thus, it does not hide data patterns well. In some senses it doesn't provide message confidentiality at all, and it is not recommended for cryptographic protocols.

wikipedia has a striking example of the degree to which ECB can reveal patterns in the plaintext. The example uses a bitmap file of an image as the plaintext message. After applying DES encryption in ECB mode, the ciphertext message can be viewed as a new bitmap image file. The new image does reveal major patterns of the original image very clearly.

Table of Contents

 About This Book

 Cryptography Terminology

 Cryptography Basic Concepts

 Introduction to AES (Advanced Encryption Standard)

 Introduction to DES Algorithm

 DES Algorithm - Illustrated with Java Programs

 DES Algorithm Java Implementation

 DES Algorithm - Java Implementation in JDK JCE

DES Encryption Operation Modes

 DES Encryption Operation Mode Introduction

What is ECB (Electronic CodeBook) Operation Mode?

 What is CBC (Cipher Block Chaining) Operation Mode?

 What is CFB (Cipher FeedBack) Operation Mode?

 What is OFB (Output FeedBack) Operation Mode?

 DES Operation Modes in JCE

 JCE DES Operation Mode Testing Program

 JCE DES Operation Mode Testing Program Result

 DES in Stream Cipher Modes

 PHP Implementation of DES - mcrypt

 Blowfish - 8-Byte Block Cipher

 Secret Key Generation and Management

 Cipher - Secret Key Encryption and Decryption

 Introduction of RSA Algorithm

 RSA Implementation using java.math.BigInteger Class

 Introduction of DSA (Digital Signature Algorithm)

 Java Default Implementation of DSA

 Private key and Public Key Pair Generation

 PKCS#8/X.509 Private/Public Encoding Standards

 Cipher - Public Key Encryption and Decryption

 MD5 Mesasge Digest Algorithm

 SHA1 Mesasge Digest Algorithm

 OpenSSL Introduction and Installation

 OpenSSL Generating and Managing RSA Keys

 OpenSSL Managing Certificates

 OpenSSL Generating and Signing CSR

 OpenSSL Validating Certificate Path

 "keytool" and "keystore" from JDK

 "OpenSSL" Signing CSR Generated by "keytool"

 Migrating Keys from "keystore" to "OpenSSL" Key Files

 Certificate X.509 Standard and DER/PEM Formats

 Migrating Keys from "OpenSSL" Key Files to "keystore"

 Using Certificates in IE (Internet Explorer)

 Using Certificates in Firefox

 Using Certificates in Google Chrome

 Outdated Tutorials

 References

 PDF Printing Version