Try implementing signature verification for elliptic curve cryptography in Java

Elliptic Curve Cryptography (ECC), which belongs to the same public key cryptography as RSA in cryptography, has been said to be a child that can be done by RSA for about 15 years. I wondered if it would end up as a secret weapon as it is, but there are no signs that it will finally start to be used, so I investigated how to implement it in Java. Java seems to have added a native provider of elliptic curve cryptography in JDK 7 and above.

Sample code

This is a signature verification sample code for the Elliptic Curve Digital Signature Algorithm (ECDSA). Key pair generation, signature creation, and signature verification are performed in order. In actual use, the person who creates the signature and the person who verifies the signature are different people, but in the sample, they are done in the same method.

package com.example;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;

import javax.xml.bind.DatatypeConverter;

public class ECDSAExample {

	/**
	 *Elliptic curve DSA signature verification sample
	 */
	public static void main(String[] args) throws Exception {
        /*
         *Elliptic curve cryptographic key pair generation
         */
		//Key pair generator
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("EC"); // Elliptic Curve
        //Random number generator
        SecureRandom randomGen = SecureRandom.getInstance("SHA1PRNG");
        //Initialize the key pair generator by specifying the key size and random number generator
        int keySize = 256;
        keyGen.initialize(keySize, randomGen);

        //Key pair generation
        KeyPair keyPair = keyGen.generateKeyPair();
        //Private key
        PrivateKey privateKey = keyPair.getPrivate();
        //Public key
        PublicKey publicKey = keyPair.getPublic();

        /*
         *Signature generation
         */
        String originalText = "This is string to sign";

        //Specify the signature generation algorithm
        Signature dsa = Signature.getInstance("SHA1withECDSA");
        //Initialization
        dsa.initSign(privateKey);
        //Signature generation
        dsa.update(originalText.getBytes("UTF-8"));
        //Extract the generated signature
        byte[] signature = dsa.sign();
        System.out.println("Signature: " + DatatypeConverter.printHexBinary(signature));

        /*
         *Signature verification
         */
        //Initialization
        dsa.initVerify(publicKey);
        //Set the target for signature verification
        dsa.update(originalText.getBytes("UTF-8"));
        //Signature verification
        boolean verifyResult = dsa.verify(signature);
        System.out.println("Verify: " + verifyResult);
    }
}

KeyPair Generator algorithm

The following can be specified for the argument of the key pair generator.

http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#KeyPairGenerator

SecureRandom random number generation algorithm

The following can be specified as the arguments of the random number generator.

http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#SecureRandom

Signature algorithm

The following can be specified as the signature algorithm.

http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#Signature

Reference source

java - Tutorial of ECDSA algorithm to sign a string - Stack Overflow https://stackoverflow.com/questions/11339788/tutorial-of-ecdsa-algorithm-to-sign-a-string Java Cryptography Architecture Standard Algorithm Name Document (for JDK 8)-#KeyPairGenerator Algorithm http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#KeyPairGenerator Java Cryptography Architecture Standard Algorithm Name Document (for JDK 8)-#SecureRandom Random Number Generator http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#SecureRandom Java Cryptographic Architecture Standard Algorithm Name Document (for JDK 8)-#Signature Algorithm http://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/StandardNames.html#Signature Appendix A (Standard Name of PRNG Algorithm) in Java Cryptographically Architectural API Specification & Reference https://docs.oracle.com/javase/jp/1.4/guide/security/CryptoSpec.html#AppA Elliptical curve cryptography in java http://rahulatjava.blogspot.jp/2014/02/elliptical-curve-cryptography-in-java.html bc-java/ECIESTest.java at master · bcgit/bc-java https://github.com/bcgit/bc-java/blob/master/prov/src/test/java/org/bouncycastle/jce/provider/test/ECIESTest.java Encryption and Decryption of Data using Elliptic Curve Cryptography( ECC ) with Bouncy Castle C# Library https://www.codeproject.com/Tips/1071190/Encryption-and-Decryption-of-Data-using-Elliptic-C