May 21, 2018 In this video we'll be learning how to create our own license keys using Python, we'll also be using our own algorithm to verify keys we create. Go to for more!

∟Java Default Implementation of DSA

∟DsaKeyGenerator.java - Generating DSA Key Pair

This section provides a tutorial example on how to using the Java default implementation of DSA (Digital Signature Algorithm) to generate DSA key pair, public key and private key.

Implementing the DSA digital signature algorithm from scratch is not easy. What we can do is to use the default implementation of DSA in Java SE 6.0.

The first Java program I wrote is to generate a DSA key pair, public key and private key:

Some notes on DsaKeyGenerator.java:

- The java.security.KeyPairGenerator.getInstance(algorithm) method is used to create a key pair generator object for the specified algorithm, 'DSA'.
- The java.security.KeyPairGenerator.initialize() method is used to initialize the key pair generator with the specified key size.
- The java.security.KeyPairGenerator.generateKeyPair() method is used to generate a new key pair.
- The java.security.Key.getEncoded() method is used to convert the key to a byte array using the default encoding.
- The java.io.FileOutputStream.write() method is used to dump the byte array to a file.

Testing result is presented in the next tutorial.

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

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

►DsaKeyGenerator.java - Generating DSA Key Pair

DSA 512-bit and 1024-bit Key Pair Examples

DsaKeyChecker.java - Reading and Checking DSA Keys

Example of DSA Key Parameters and Properties

java.security.Signature - The Data Signing Class

DsaSignatureGenerator.java - Generating DSA Digital Signature

## Product Key Generation Algorithm In Java 1

DsaSignatureGenerator.java Test Results

DsaSignatureVerifier.java - Verifying DSA Digital Signature

DsaSignatureVerifier.java Test Results

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

Outdated Tutorials

References

Full Version in PDF/EPUB

**Key generation** is the process of generating keys for cryptography. The key is used to encrypt and decrypt data whatever the data is being encrypted or decrypted.

## Product Key Generation Algorithm In Java Pdf

Modern cryptographic systems include symmetric-key algorithms (such as DES and AES) and public-key algorithms (such as RSA). Symmetric-key algorithms use a single shared key; keeping data secret requires keeping this key secret. Public-key algorithms use a public key and a private key. The public key is made available to anyone (often by means of a digital certificate). A sender will encrypt data with the public key; only the holder of the private key can decrypt this data.

Since public-key algorithms tend to be much slower than symmetric-key algorithms, modern systems such as TLS and its predecessor SSL as well as the SSH use a combination of the two in which:

- One party receives the other's public key, and encrypts a small piece of data (either a symmetric key or some data that will be used to generate it).
- The remainder of the conversation (the remaining party) uses a (typically faster) symmetric-key algorithm for encryption.

The simplest method to read encrypted data is a brute force attack–simply attempting every number, up to the maximum length of the key. Therefore, it is important to use a sufficiently long key length; longer keys take exponentially longer time to attack, making a brute force attack invisible and impractical.

Currently, commonly used key lengths are:

- 128-bits for symmetric key algorithms.
- 1024-bits for public-key algorithms.

## Key generation algorithms[changechange source]

In computer cryptography keys are integers. In some cases keys are randomly generated using a random number generator (RNG) or pseudorandom number generator (PRNG), the latter being a computeralgorithm that produces data which appears random under analysis. Some types the PRNGs algorithms utilize system entropy to generate a seed data, such seeds produce better results, since this makes the initial conditions of the PRNG much more difficult for an attacker to guess.

In other situations, the key is created using a passphrase and a *key generation algorithm*, using a cryptographic hash function such as SHA-1.

## Related pages[changechange source]

- Distributed key generation: For some protocols no party should be in the sole possession of the secret key. Rather, during
*distributed key generation*every party obtains a share of the key. A threshold of the participating parties need to work together in order to achieve a cryptographic task, such as decrypting a message.