RSA Signature Generation : RSA algorithm « Security « Java Tutorial

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import java.security.Security;
import java.security.Signature;

public class MainClass {
  public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA", "BC");

    keyGen.initialize(512, new SecureRandom());

    KeyPair keyPair = keyGen.generateKeyPair();
    Signature signature = Signature.getInstance("SHA1withRSA", "BC");

    signature.initSign(keyPair.getPrivate(), new SecureRandom());

    byte[] message = "abc".getBytes();
    signature.update(message);

    byte[] sigBytes = signature.sign();
    signature.initVerify(keyPair.getPublic());
    signature.update(message);
    System.out.println(signature.verify(sigBytes));
  }
}

36.38.RSA algorithm
	36.38.1.	Basic RSA example.
	36.38.2.	RSA example with random key generation.
	36.38.3.	RSA example with PKCS #1 Padding.
	36.38.4.	RSA example with OAEP Padding and random key generation.
	36.38.5.	An example of using RSA to encrypt a single asymmetric key.
	36.38.6.	Simple Digital Signature Example
	36.38.7.	Creates a 1024 bit RSA key pair and stores it to the filesystem as two files
	36.38.8.	RSA Signature Generation
	36.38.9.	An RSA sample application