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In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

Furthermor your code has a second significant bug:

You are converting a byte array with binary content to a String.

Never ever convert binary data to a String!

Strings are for string characters, not binary data. If you want to pack binary data into a String encode it to printable characters for example using Hex or Base64.

The following example uses the hexadecimal encoder fro org.apache.common.codec package - a third party library with has to be installed.

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(2048);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + org.apache.commons.codec.binary.Hex.encodeHexString(encryptedBytes));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}

In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

Furthermor your code has a second significant bug:

You are converting a byte array with binary content to a String.

Never ever convert binary data to a String!

Strings are for string characters, not binary data. If you want to pack binary data into a String encode it to printable characters for example using Hex or Base64.

The following example uses the hexadecimal encoder fro org.apache.common.codec package - a third party library with has to be installed.

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(2048);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + new String(org.apache.commons.codec.binary.Hex.encodeHex(encryptedBytes)));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}

In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

Furthermor your code has a second significant bug:

You are converting a byte array with binary content to a String.

Never ever convert binary data to a String!

Strings are for string characters, not binary data. If you want to pack binary data into a String encode it to printable characters for example using Hex or Base64.

The following example uses the hexadecimal encoder fro org.apache.common.codec package - a third party library with has to be installed.

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(1024);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + org.apache.commons.codec.binary.Hex.encodeHexString(encryptedBytes));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}

In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

Furthermor your code has a second significant bug:

You are converting a byte array with binary content to a String.

Never ever convert binary data to a String!

Strings are for string characters, not binary data. If you want to pack binary data into a String encode it to printable characters for example using Hex or Base64.

The following example uses the hexadecimal encoder fro org.apache.common.codec package - a third party library with has to be installed.

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(2048);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + org.apache.commons.codec.binary.Hex.encodeHexString(encryptedBytes));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}

In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

In RSA you should use the public key for encryption and the private key for decryption.

Your sample code uses for encryption and decryption the public key - this can not work.

Hence in the decryption part you should initialize the cipher this way:

cipher1.init(Cipher.DECRYPT_MODE, privateKey);

Furthermor your code has a second significant bug:

You are converting a byte array with binary content to a String.

Never ever convert binary data to a String!

Strings are for string characters, not binary data. If you want to pack binary data into a String encode it to printable characters for example using Hex or Base64.

The following example uses the hexadecimal encoder fro org.apache.common.codec package - a third party library with has to be installed.

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(1024);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + org.apache.commons.codec.binary.Hex.encodeHexString(encryptedBytes));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}