**Cryptography Tutorials - Herong's Tutorial Examples** - Version 5.40, by Dr. Herong Yang

DES Encryption Operation Modes

This chapter provides tutorial examples and notes about DES encryption operation modes. Topics include how different blocks of plaintext can be coupled together to improve the strength of the DES encryption algorithm; ECB (Electronic CodeBook), CBC (Cipher Block Chaining), CFB (Cipher FeedBack), and OFB (Output FeedBack) 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?

Conclusion

- DES operation modes are ways to couple previous plaintext blocks with the current plaintext block to improve the strength of the encryption.
- Initial vector is used to parameterize the operation modes.
- Sun JCE implementation of DES operation modes work as expected.

Table of Contents

Introduction to AES (Advanced Encryption Standard)

DES Algorithm - Illustrated with Java Programs

DES Algorithm Java Implementation

DES Algorithm - Java Implementation in JDK JCE

►DES Encryption Operation Modes

PHP Implementation of DES - mcrypt

Blowfish - 8-Byte Block Cipher

Secret Key Generation and Management

Cipher - Secret Key Encryption and Decryption

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

OpenSSL Introduction and Installation

OpenSSL Generating and Managing RSA Keys

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"