数字签名 – 带有密钥的消息摘要算法 作用：验证数据完整性、认证数据来源、抗否认（OSI参考模型） 私钥签名，公钥验证 RSA 包含非对称算法和数字签名算法 实现代码:
//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(); //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(str.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(str.getBytes()); boolean falg = signature.verify(result); System.out.println("JDK RSA VERIFY:"+falg); DSA DSS -- 数字签名标准 DSA仅包含数字签名 ECDSA 椭圆曲线数字签名算法，JDK1.7之后才有的内容 实现方式和RSA一致 只需将指定地方改为EC,再在首句加上Security.addProvider(new BouncyCastlePQCProvider());即可 JAVA加解密算法源码:http://download.csdn.net/detail/jacxuan/9774737