数字签名(Digital Signature)
数字签名也叫公钥数字签名,是信息发送者产生的别人无法伪造的一段数字串,这段数字串是对信息发送者发送信息真实性的一个有效证明。
数字签名:
数字签名是电子签名的一种形式,是电子签名的一个子集。
电子签名是指以电子形式存在于任何数据电文中,用来识别签名者身份并表明签名者识别其中内容的数据,狭义的电子签名是使用PKI系统的数字签名。
数字证书(Certificate Authority)可用于数字签名。
数字签名,带有密钥(公钥、私钥)的消息摘要算法,验证数据的完整性、来源和抗否认。
签名原理
数字签名,只有信息的发送者才能产生的别人无法伪造的一段数字串,这段数字串同时也是对信息的发送者发送信息真实性的一个有效证明。
数字签名,一般是非对称密钥加密技术与数字摘要技术的结合应用。
数字签名算法
业界比较常用的数字签名算法有三种:RSA、DSA、ECDSA。
1、RSA算法,非对称加密算法。
2、DSA算法,在RSA之后提出的数字签名算法,和RSA相比,DSA只能用于数字签名,不能用于数据的加密和解密。
3、ECDSA算法,是ECC算法和DSA算法的结合,相比来说,它有计算快、强度高、签名短的优点。
Java下,RSA的实现:
Java下,ECDSA的实现:
RSA的代码案例:
import org.apache.commons.codec.binary.Hex;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
public class RSADemo {
private static String src = "security rsa";
public static void main(String[] args) {
jdkRSA();
}
public static void jdkRSA() {
try {
//1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
keyPairGenerator.initialize(512);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
RSAPublicKey rsaPublicKey = (RSAPublicKey)keyPair.getPublic();
RSAPrivateKey rsaPrivateKey = (RSAPrivateKey)keyPair.getPrivate();
//2.执行签名
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(rsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Signature signature = Signature.getInstance("MD5withRSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
byte[] result = signature.sign();
System.out.println("jdk rsa sign : " + Hex.encodeHexString(result));
//3.验证签名
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(rsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
signature = Signature.getInstance("MD5withRSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
boolean bool = signature.verify(result);
System.out.println("jdk rsa verify : " + bool);
} catch (Exception e) {
e.printStackTrace();
}
}
}
DSA的代码案例:
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import org.apache.commons.codec.binary.Hex;
public class DSADemo {
private static String src = "security dsa";
public static void main(String[] args) {
jdkDSA();
}
public static void jdkDSA() {
try {
//1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DSA");
keyPairGenerator.initialize(512);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
DSAPublicKey dsaPublicKey = (DSAPublicKey) keyPair.getPublic();
DSAPrivateKey dsaPrivateKey = (DSAPrivateKey)keyPair.getPrivate();
//2.执行签名
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(dsaPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("DSA");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Signature signature = Signature.getInstance("SHA1withDSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
byte[] result = signature.sign();
System.out.println("jdk dsa sign : " + Hex.encodeHexString(result));
//3.验证签名
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(dsaPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("DSA");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
signature = Signature.getInstance("SHA1withDSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
boolean bool = signature.verify(result);
System.out.println("jdk dsa verify : " + bool);
} catch (Exception e) {
e.printStackTrace();
}
}
}
ECDSA的代码案例:
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import org.apache.commons.codec.binary.Hex;
public class ECDSADemo {
private static String src = "security ecdsa";
public static void main(String[] args) {
jdkECDSA();
}
public static void jdkECDSA() {
try {
//1.初始化密钥
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC");
keyPairGenerator.initialize(256);
KeyPair keyPair = keyPairGenerator.generateKeyPair();
ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic();
ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate();
//2.执行签名
PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());
KeyFactory keyFactory = KeyFactory.getInstance("EC");
PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec);
Signature signature = Signature.getInstance("SHA1withECDSA");
signature.initSign(privateKey);
signature.update(src.getBytes());
byte[] result = signature.sign();
System.out.println("jdk ecdsa sign : " + Hex.encodeHexString(result));
//3.验证签名
X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded());
keyFactory = KeyFactory.getInstance("EC");
PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
signature = Signature.getInstance("SHA1withECDSA");
signature.initVerify(publicKey);
signature.update(src.getBytes());
boolean bool = signature.verify(result);
System.out.println("jdk ecdsa verify : " + bool);
} catch (Exception e) {
e.printStackTrace();
}
}
}