非對稱加密演算法是相對於對稱加密演算法來說的,對於對稱加密演算法請查閱之前的總結,今天為大家介紹一下dh演算法,dh是一種金鑰交換演算法,接收方根據傳送方加密時的金鑰,生成接收方解密金鑰。下面就一起來學習一下吧:
初始化傳送方金鑰:
keypairgenerator sendkeypairgenerator = keypairgenerator.getinstance("dh");sendkeypairgenerator.initialize(512);
keypair sendkeypair =sendkeypairgenerator.generatekeypair();
byte sendpublickeyenc = sendkeypair.getpublic().getencoded();//
生成傳送方公鑰,傳送給接收方(網路、檔案...)
初始化接收方金鑰:
keyfactory receiverkeyfactory = keyfactory.getinstance("dh");x509encodedkeyspec x509encodedkeyspec = new
x509encodedkeyspec(sendpublickeyenc);
publickey receivepublickey =receiverkeyfactory.generatepublic(x509encodedkeyspec);
dhparameterspec dhparameterspec =((dhpublickey)receivepublickey).getparams();
keypairgenerator receiverkeypairgenerator = keypairgenerator.getinstance("dh");
receiverkeypairgenerator.initialize(dhparameterspec);
keypair receiverkeypair =receiverkeypairgenerator.generatekeypair();
privatekey receiverprivatekey =receiverkeypair.getprivate();
byte receiverpublickeyenc = receiverkeypair.getpublic().getencoded();
構建接收方金鑰:
keyagreement receiverkeyagreement = keyagreement.getinstance("dh");receiverkeyagreement.init(receiverprivatekey);
receiverkeyagreement.dophase(receivepublickey,
true
);
secretkey receiverdeskey = receiverkeyagreement.generatesecret("des");//
接收方key
構建傳送方金鑰:
keyfactory sendkeyfactory = keyfactory.getinstance("dh");x509encodedkeyspec = new
x509encodedkeyspec(receiverpublickeyenc);
publickey sendpublickey =sendkeyfactory.generatepublic(x509encodedkeyspec);
keyagreement sendkeyagreement = keyagreement.getinstance("dh");
sendkeyagreement.init(sendkeypair.getprivate());
sendkeyagreement.dophase(sendpublickey,
true
);
secretkey senddeskey = sendkeyagreement.generatesecret("des");//
傳送方key
傳送方加密:
cipher sendcipher = cipher.getinstance("des");sendcipher.init(cipher.encrypt_mode, senddeskey);
byte sendresult =sendcipher.dofinal(src.getbytes());
system.out.println("sendresult :"+hex.encodehexstring(sendresult));
接收方解密:
cipher receivercipher = cipher.getinstance("des");receivercipher.init(cipher.decrypt_mode, receiverdeskey);
byte receiverresult =receivercipher.dofinal(sendresult);
system.out.println("receiverresult : "+new string (receiverresult));
基於金鑰交換的非對稱加密演算法(dh),到這裡就總結完畢了。
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