這篇文章主要介紹了java 對稱加密算法實現詳解,文中通過示例代碼介紹的非常詳細,對大家的學習或者工作具有一定的參考學習價值,需要的朋友可以參考下
前言
對於信息的加密方式多種多樣,之前爲大家介紹了一種自己設計的加密方式,有興趣的朋友可以欣賞一下,歡迎給予指點。今天爲大家介紹一下對稱加密方式,所謂對稱加密指的是加密和解密方式呈對稱格式,即解密是加密的逆過程,下面我們就看一下:DES、3DES、AES、PBE這四種方式,他們的加密強度依次遞增。好吧閒話少說,上代碼:
首先我們先看一下DES:
package cn.edu.hpu.des; import java.security.Key; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.DESKeySpec; public class jdk_DES { private static final String src = "I Love You !"; public static void main(String [] args){ jdk_DES.jdkDES(); } @SuppressWarnings("static-access") public static void jdkDES(){ try { //獲得KEY KeyGenerator keyGenerator = KeyGenerator.getInstance("DES"); keyGenerator.init(56);//設置爲默認值56即可 //獲得KEY對象 SecretKey secrekeyone = keyGenerator.generateKey(); byte [] byteskey = secrekeyone.getEncoded(); //KEY轉換 DESKeySpec deskeyspec = new DESKeySpec(byteskey); SecretKeyFactory factory = SecretKeyFactory.getInstance("DES"); Key secerkeytwo = factory.generateSecret(deskeyspec); //加密 Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding"); cipher.init(cipher.ENCRYPT_MODE, secerkeytwo);//設置模式爲加密 byte[] result = cipher.doFinal(src.getBytes()); System.out.println("jdkEDS:"+result.toString()); //解密 cipher.init(cipher.DECRYPT_MODE, secerkeytwo);//設置模式爲解密 result = cipher.doFinal(result); System.out.println("jdkEDS:"+new String(result)); } catch (Exception e) { e.printStackTrace(); } } }
運行結果:
第二種3重DES:
package cn.edu.hpu.des; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.DESKeySpec; public class jdk_3DES { private static final String src = "I Love You !"; public static void main(String [] args){ jdk_3DES.jdk3DES(); } @SuppressWarnings("static-access") public static void jdk3DES(){ try { //獲得KEY KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede"); //keyGenerator.init(112);//設置密鑰長度,默認值爲168,也可設置爲112 keyGenerator.init(new SecureRandom());//設置爲默認值 //獲得KEY對象 SecretKey secrekeyone = keyGenerator.generateKey(); byte [] byteskey = secrekeyone.getEncoded(); //KEY轉換 DESKeySpec deskeyspec = new DESKeySpec(byteskey); SecretKeyFactory factory = SecretKeyFactory.getInstance("DES"); Key secerkeytwo = factory.generateSecret(deskeyspec); //加密 Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding"); cipher.init(cipher.ENCRYPT_MODE, secerkeytwo);//設置模式爲加密 byte[] result = cipher.doFinal(src.getBytes()); System.out.println("jdkEDS:"+result.toString()); //解密 cipher.init(cipher.DECRYPT_MODE, secerkeytwo);//設置模式爲解密 result = cipher.doFinal(result); System.out.println("jdkEDS:"+new String(result)); } catch (Exception e) { e.printStackTrace(); } } }
運行結果:
第三種AES:
package cn.edu.hpu.aes; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; public class jdk_AES { private static final String src = "I Love You !"; public static void main(String [] args){ AES(); } public static void AES(){ try { //獲得key KeyGenerator keyGenerator = KeyGenerator.getInstance("AES"); keyGenerator.init(new SecureRandom());//默認密鑰長度爲: SecretKey secretKey = keyGenerator.generateKey(); byte [] keyBytes = secretKey.getEncoded(); //key轉換 Key key = new SecretKeySpec(keyBytes, "AES"); //加密 Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key); byte[] result = cipher.doFinal(src.getBytes()); System.out.println("AES="+result.toString()); //解密 cipher.init(Cipher.DECRYPT_MODE, key); result = cipher.doFinal(result); System.out.println("AES="+new String(result)); } catch (Exception e) { e.printStackTrace(); } } }
運行結果:
最後一種PBE:
package cn.edu.hpu.pbe; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.PBEKeySpec; import javax.crypto.spec.PBEParameterSpec; public class jdk_PBE { public static final String src = "I Love You !"; public static void main(String [] args){ jdkPBE(); } private static void jdkPBE(){ try { //初始化鹽 SecureRandom random = new SecureRandom(); byte [] salt = random.generateSeed(8); //口令和密鑰 String password = "imooc"; PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray());//生成密鑰轉換對象 SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHMD5andDES"); Key key = factory.generateSecret(pbeKeySpec); //加密 PBEParameterSpec pbeParameterSpec = new PBEParameterSpec(salt, 100);//實例化PBE對象的一個輸入的材料:參數分別爲"鹽和迭代次數" Cipher cipher = Cipher.getInstance("PBEWITHMD5andDES"); cipher.init(Cipher.ENCRYPT_MODE, key, pbeParameterSpec); byte [] result = cipher.doFinal(src.getBytes()); System.out.println("PBE:"+result.toString()); //解密 cipher.init(Cipher.DECRYPT_MODE, key, pbeParameterSpec); result = cipher.doFinal(result); System.out.println("PBE:"+new String(result)); } catch (Exception e) { e.printStackTrace(); } } }
運行結果:
結語
對於以上四種方式,PBE是一種較安全的加密方式,對加密起絕定作用的是鹽和password,決定着加密的結果。以上即使要爲大家介紹的對稱加密方式,哪位有更好的方式,還望指教。
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