keypair.java

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.Signature;
import java.util.Scanner;
public class CreatingDigitalSignature {
public static void main(String args[]) throws Exception {
Scanner sc = new
Scanner(System.in);
System.out.println("Enter some
text"); String msg = sc.nextLine();
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("DSA");
keyPairGen.initialize(2048);
KeyPair pair =
keyPairGen.generateKeyPair(); PrivateKey
privKey = pair.getPrivate();
Signature sign = Signature.getInstance("SHA256withDSA");
sign.initSign(privKey);
byte[] bytes =
"msg".getBytes();
sign.update(bytes);
byte[] signature = sign.sign();
System.out.println("Digital signature for given text: "+new String(signature,
"UTF8"));
}
}
OUTPUT:
Enter some
text Hi how are
you
Digital signature for given text: 0=@gRD???-?.???? /yGL?i??a!?