Java Key Pair Generator Algorithms

14.12.2020by admin

Java Key Pair Generator Algorithms Rating: 5,5/10 6681 votes

The Java KeyPairGenerator class (java.security.KeyPairGenerator) is used to generate asymmetric encryption / decryption key pairs. An asymmetric key pair consists of two keys. The first key is typically used to encrypt data. The second key which is used to decrypt data encrypted with the first key.

Java Key Pair Generator Algorithms Download
Java Algorithms Examples
Java Algorithm Code

Getting the public key from the private key is in some algorithms just a matter of multiplication in the group of the elliptic curve. – Henry Oct 30 '13 at 6:53. Plz don't say no, I started the work, to proceed I need to generate public key. GetInstance(String algorithm) The getInstance method of java.security.KeyPairGenerator class is used to return a KeyPairGenerator object that generates public/private key pairs for the specified algorithm. This method traverses the list of registered security Providers, starting with the most preferred Provider.

Public Key, Private Key Type Key Pairs

The most commonly known type of asymmetric key pair is the public key, private key type of key pair. The private key is used to encrypt data, and the public key can be used to decrypt the data again. Actually, you could also encrypt data using the public key and decrypt it using the private key.

The private key is normally kept secret, and the public key can be made publicly available. Thus, if Jack encrypts some data with his private key, everyone in possession of Jack's public key can decrypt it.

Creating a KeyPairGenerator Instance

To use the Java KeyPairGenerator you must first create a KeyPairGenerator instance. Creating a KeyPairGenerator instance is done by calling the method getInstance() method. Here is an example of creating a Java KeyPairGenerator instance:

The getInstance()Photoshop cs6 license key generator mac. method takes the name of the encryption algorithm to generate the key pair for. In this example we use the name RSA.

Initializing the KeyPairGenerator

Depending on the algorithm the key pair is generated for, you may have to initialize the KeyPairGenerator instance. Initializing the KeyPairGenerator is done by calling its initialize() method. Here is an example of initializing a Java KeyPairGenerator instance:

This example initializes the KeyPairGenerator to generate keys of 2048 bits in size.

Generating a Key Pair

To generate a KeyPair with a KeyPairGenerator you call the generateKeyPair() method. Here is an example of generating a KeyPair with the KeyPairGenerator:

Right 1

This class defines the Service Provider Interface (SPI) for the KeyPairGenerator class, which is used to generate pairs of public and private keys.

All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a key pair generator for a particular algorithm.

In case the client does not explicitly initialize the KeyPairGenerator (via a call to an initialize method), each provider must supply (and document) a default initialization. For example, the Sun provider uses a default modulus size (keysize) of 1024 bits.

See Also:: KeyPairGenerator, AlgorithmParameterSpec

Constructor Summary
`KeyPairGeneratorSpi()`

Method Summary
`abstract KeyPair`	`generateKeyPair()` Generates a key pair.
`void`	`initialize(AlgorithmParameterSpec params, SecureRandom random)` Initializes the key pair generator using the specified parameter set and user-provided source of randomness.
`abstract void`	`initialize(int keysize, SecureRandom random)` Initializes the key pair generator for a certain keysize, using the default parameter set.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

KeyPairGeneratorSpi

Method Detail

initialize

Initializes the key pair generator for a certain keysize, using the default parameter set.

Parameters:: keysize - the keysize. This is an algorithm-specific metric, such as modulus length, specified in number of bits.; random - the source of randomness for this generator.
Throws:: InvalidParameterException - if the keysize is not supported by this KeyPairGeneratorSpi object.

initialize

Initializes the key pair generator using the specified parameter set and user-provided source of randomness.

This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.) It may be overridden by a provider to initialize the key pair generator. Such an override is expected to throw an InvalidAlgorithmParameterException if a parameter is inappropriate for this key pair generator. If this method is not overridden, it always throws an UnsupportedOperationException.

Parameters:: params - the parameter set used to generate the keys.; random - the source of randomness for this generator.
Throws:: InvalidAlgorithmParameterException - if the given parameters are inappropriate for this key pair generator.
Since:: 1.2