Rsa Algorithm For Key Generation And Cipher Verification In Java

18.12.2020

Rsa Algorithm For Key Generation And Cipher Verification In Java Rating: 8,6/10 5166 reviews

Most common used algorithm is RSA ALGORITHM. Named after Rivest,Shamir and Adleman; Understanding and making working example for RSA encryption and decryption using public and private key takes lots lots of time for me. Believe me, It's complex stuff:) Steps 1: Let's Break down tasks which helps us to encrypt and decrypt data using RSA Algorithm.
Java Program on RSA Algorithm. RSA algorithm is an asymmetric cryptography algorithm. Asymmetric means that it works on two different keys i.e. Public Key and Private Key.As the name suggests that the Public Key is given to everyone and Private Key is kept private.

Jul 20, 2017 Write program in C or Java to implement RSA algorithm for key generation and cipher verification Huzaif Sayyed July 20, 2017 BE INFO CYBER SECURITY AND MACHINE LEARNING PROGRAMS RSA is algorithm used by modern computers to encrypt and decrypt messages. It is an asymmetric cryptographic algorithm.

Example of RSA generation, sign, verify, encryption, decryption and keystores in Java

RsaExample.java

importjavax.crypto.Cipher;

importjava.io.InputStream;

importjava.security.*;

importjava.util.Base64;

import staticjava.nio.charset.StandardCharsets.UTF_8;

publicclassRsaExample {

publicstaticKeyPairgenerateKeyPair() throwsException {

KeyPairGenerator generator =KeyPairGenerator.getInstance('RSA');

generator.initialize(2048, newSecureRandom());

KeyPair pair = generator.generateKeyPair();

return pair;

}

publicstaticKeyPairgetKeyPairFromKeyStore() throwsException {

//Generated with:

// keytool -genkeypair -alias mykey -storepass s3cr3t -keypass s3cr3t -keyalg RSA -keystore keystore.jks

InputStream ins =RsaExample.class.getResourceAsStream('/keystore.jks');

KeyStore keyStore =KeyStore.getInstance('JCEKS');

keyStore.load(ins, 's3cr3t'.toCharArray()); //Keystore password

KeyStore.PasswordProtection keyPassword =//Key password

newKeyStore.PasswordProtection('s3cr3t'.toCharArray());

KeyStore.PrivateKeyEntry privateKeyEntry = (KeyStore.PrivateKeyEntry) keyStore.getEntry('mykey', keyPassword);

java.security.cert.Certificate cert = keyStore.getCertificate('mykey');

PublicKey publicKey = cert.getPublicKey();

PrivateKey privateKey = privateKeyEntry.getPrivateKey();

returnnewKeyPair(publicKey, privateKey);

}

publicstaticStringencrypt(StringplainText, PublicKeypublicKey) throwsException {

Cipher encryptCipher =Cipher.getInstance('RSA');

encryptCipher.init(Cipher.ENCRYPT_MODE, publicKey);

byte[] cipherText = encryptCipher.doFinal(plainText.getBytes(UTF_8));

returnBase64.getEncoder().encodeToString(cipherText);

}

publicstaticStringdecrypt(StringcipherText, PrivateKeyprivateKey) throwsException {

byte[] bytes =Base64.getDecoder().decode(cipherText);

Cipher decriptCipher =Cipher.getInstance('RSA');

decriptCipher.init(Cipher.DECRYPT_MODE, privateKey);

returnnewString(decriptCipher.doFinal(bytes), UTF_8);

}

publicstaticStringsign(StringplainText, PrivateKeyprivateKey) throwsException {

Signature privateSignature =Signature.getInstance('SHA256withRSA');

privateSignature.initSign(privateKey);

privateSignature.update(plainText.getBytes(UTF_8));

byte[] signature = privateSignature.sign();

returnBase64.getEncoder().encodeToString(signature);

}

publicstaticbooleanverify(StringplainText, Stringsignature, PublicKeypublicKey) throwsException {

Signature publicSignature =Signature.getInstance('SHA256withRSA');

publicSignature.initVerify(publicKey);

publicSignature.update(plainText.getBytes(UTF_8));

byte[] signatureBytes =Base64.getDecoder().decode(signature);

return publicSignature.verify(signatureBytes);

}

publicstaticvoidmain(String. argv) throwsException {

//First generate a public/private key pair

KeyPair pair = generateKeyPair();

//KeyPair pair = getKeyPairFromKeyStore();

//Our secret message

String message ='the answer to life the universe and everything';

//Encrypt the message

String cipherText = encrypt(message, pair.getPublic());

//Now decrypt it

String decipheredMessage = decrypt(cipherText, pair.getPrivate());

System.out.println(decipheredMessage);

//Let's sign our message

String signature = sign('foobar', pair.getPrivate());

//Let's check the signature

boolean isCorrect = verify('foobar', signature, pair.getPublic());

System.out.println('Signature correct: '+ isCorrect);

}

Rsa Algorithm For Key Generation And Cipher Verification In Java Key

commented Oct 17, 2019

Rsa Algorithm For Key Generation And Cipher Verification In Java Version

It's good thank you so much , How can i create base64 like jwt (header,body,sign) ? Windows 7 home premium sp1 key generator.

commented Nov 26, 2019

Rsa algorithm for key generation and cipher verification in java pdf

Thanks for the code. One issue - using openjdk version '11.0.5-ea' 2019-10-15 requires the KeyStore.getInstance('JCEKS') code to be KeyStore.getInstance('PKCS12').

commented Dec 29, 2019

Free download mapdraw for mac. Windows 7 ultimate cd key 64 bit generator. @stdunbar: It depends on your keyStore creation.

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