Java 7中的椭圆曲线密码术实现

Question

我试图在java中实现Elliptic Curve Cryptography(ECC),因为java 7提供了支持椭圆曲线加密(ECC)的本机提供程序SunEC但是我总是收到错误java.security.InvalidKeyException:无效的密钥长度:91字节,因为椭圆我正在创建的曲线是不合适的.

我使用java 7我的任务是使用ECC生成加密和解密密钥

package com.acc;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.Provider;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Security;
import java.security.Signature;
import java.security.spec.ECGenParameterSpec;
import java.security.spec.ECParameterSpec;
import java.security.spec.EllipticCurve;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.spec.DESKeySpec;


public class TestECC {

    public static void main(String args[]) {
        try {
            Provider p[] = Security.getProviders();
            Provider p1 = Security.getProvider("SunEC");
            System.out.println(p1.getName());
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC", "SunEC");
            System.out.println(kpg.getAlgorithm());

            Cipher cipher = Cipher.getInstance("DES");
            System.out.println("provider=" + cipher.getProvider());

            ECGenParameterSpec ecsp = new ECGenParameterSpec("sect163r2");

            kpg.initialize(ecsp);
            KeyPair kyp = kpg.genKeyPair();
            PublicKey pubKey = kyp.getPublic();

            PrivateKey privKey = kyp.getPrivate();
            System.out.println(cipher.getProvider());

            cipher.init(Cipher.ENCRYPT_MODE, pubKey);

            String cleartextFile = "cleartext.txt";
            String ciphertextFile = "ciphertextECIES.txt";

            byte[] block = new byte[64];
            FileInputStream fis = new FileInputStream(cleartextFile);
            FileOutputStream fos = new FileOutputStream(ciphertextFile);
            CipherOutputStream cos = new CipherOutputStream(fos, cipher);

            int i;
            while ((i = fis.read(block)) != -1) {
                cos.write(block, 0, i);
            }
            cos.close();

            // Decrypt

            String cleartextAgainFile = "cleartextAgainECIES.txt";

            cipher.init(Cipher.DECRYPT_MODE, privKey, ecsp);

            fis = new FileInputStream(ciphertextFile);
            CipherInputStream cis = new CipherInputStream(fis, cipher);
            fos = new FileOutputStream(cleartextAgainFile);

            while ((i = cis.read(block)) != -1) {
                fos.write(block, 0, i);
            }
            fos.close();

        } catch (Exception e) {
            System.out.println(e);
        }
    }

}

输出:SunEC EC提供程序= SunJCE版本1.7 SunJCE版本1.7 java.security.InvalidKeyException:无效密钥长度:91字节

你能帮忙用ECC曲线和算法来使用

Answer 1

从我读到的,你试图:

• 使用ECC生成随机密钥对
• 使用ECC私钥作为DES对称密钥进行加密
• 使用ECC公钥作为DES对称密钥进行解密
• 期望结果是往返

这是行不通的 - DES是一种对称算法; 它要求使用相同的56位密钥进行加密和解密.向它扔一个ECC密钥不会神奇地让它接受两个操作的不同密钥!