Blowfish Cipher Algorithm

Cryptography Tutorials - Herong's Tutorial Examples

∟Blowfish - 8-Byte Block Cipher

∟Blowfish Cipher Algorithm

This section describes the Blowfish cipher algorithm - A 16-round Feistel cipher with block size of 64 bits developed by Bruce Schneier in 1993.

Blowfish - A 16-round Feistel cipher with block size of 64 bits.

Blowfish was developed by Bruce Schneier in 1993. Here is the algorithm presented in Bruce's paper:

Input: 
   T: 64 bits of clear text
   P1, P2, ..., P18: 18 sub-keys
   F(): Round function
   
Output: 
   C: 64 bits of cipher text

Algorithm:
   (xL, xR) = T, dividing T into two 32-bit parts
   Loop on i from = 1 to 16
      xL = xL XOR Pi
      xR = F(xL) XOR xR
      Swap xL and xR
   End of loop
   Swap xL and xR
   xR = xR XOR P17
   xL = xL XOR P18
   C = (xL, xR)

The round function F(A) is defined as:

Input: 
   A: 32-bit input data
   S1[], S2[], S3[], S4[]: 4 S-box lookup tables, 256 long each
   
Output
   B = f(A): 32-bit output data

Algorithm
   (a, b, c, d) = A, dividing L into four 8-bit parts
   B = ( (S1[a] + S2[b] mod 2**32) XOR S3[c] ) + S[d] mod 2**32

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 in Stream Cipher Modes

PHP Implementation of DES - mcrypt

►Blowfish - 8-Byte Block Cipher

What Is Block Cipher?

►Blowfish Cipher Algorithm

Key Schedule (Sub-Keys Generation) Algorithm

BlowfishJ - Java Implementation by Markus Hahn

Blowfish Decryption Algorithm

First 8336 Hex Digits of PI

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

Using Certificates in Google Chrome

Using Certificates in Firefox

Archived Tutorials

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