I have the following JAVA code for string encryption and decryption:
public class AES {
private SecretKeySpec setKey(String myKey)
{
try {
byte[] key = myKey.getBytes("UTF-8");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
key = sha.digest(key);
key = Arrays.copyOf(key, 16);
SecretKeySpec secretKey = new SecretKeySpec(key, "AES");
return secretKey;
}
catch (NoSuchAlgorithmException e) {
return null;
}
catch (UnsupportedEncodingException e) {
return null;
}
}
synchronized public String encrypt(String strToEncrypt, String secret)
{
try
{
SecretKeySpec secretKey = setKey(secret);
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
}
catch (Exception e)
{
return null;
}
return null;
}
synchronized public String decrypt(String strToDecrypt, String secret) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException
{
SecretKeySpec secretKey = setKey(secret);
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
}
When I use my class on the string "test" and a secret key ("d%D*G-JaXdRgUkXs") for example, I get:
D+BhlzXKsINiKja6ZsITWQ==
I have tried to make the same encryption (AES/ECB/PKCS5Padding) with the same secret key in an online tool such as https://8gwifi.org/CipherFunctions.jsp,
but I get a different result:
Nwha9Dgv9IaN4W39C6c0cQ==
What I am missing?
Try this. You are using SHA-1 algorithm to generate digest and then assigning to it to SecretKeySpec to generate secrete key. this will give you the answer that this website gives.
public class Main {
public static void main(String[] args) {
Main main = new Main();
System.out.println(main.encrypt("test","d%D*G-JaXdRgUkXs"));
}
private SecretKeySpec setKey(String myKey)
{
try {
byte[] key = myKey.getBytes("UTF-8");
key = Arrays.copyOf(key, 16);
SecretKeySpec secretKey = new SecretKeySpec(key, "AES");
return secretKey;
}
catch (UnsupportedEncodingException e) {
return null;
}
}
synchronized public String encrypt(String strToEncrypt, String secret)
{
try
{
SecretKeySpec secretKey = setKey(secret);
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
}
catch (Exception e)
{
return null;
}
}
synchronized public String decrypt(String strToDecrypt, String secret) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException
{
SecretKeySpec secretKey = setKey(secret);
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
}
}
If you run this code you will get below result
Nwha9Dgv9IaN4W39C6c0cQ==
Related
this code encryption/decryption dynamic data that entered by user:
private final String characterEncoding = "UTF-8";
private final String cipherTransformation = "AES/CBC/PKCS5Padding";
private final String aesEncryptionAlgorithm = "AES";
public String encrypt(String plainText, String key) throws UnsupportedEncodingException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException{
byte[] plainTextbytes = plainText.getBytes(characterEncoding);
byte[] keyBytes = getKeyBytes(key);
return Base64.encodeToString(encrypt(plainTextbytes,keyBytes, keyBytes), Base64.DEFAULT);
}
public String decrypt(String encryptedText, String key) throws KeyException, GeneralSecurityException, GeneralSecurityException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, IOException {
byte[] cipheredBytes = Base64.decode(encryptedText, Base64.DEFAULT);
byte[] keyBytes = getKeyBytes(key);
return new String(decrypt(cipheredBytes, keyBytes, keyBytes), characterEncoding);
}
public byte[] decrypt(byte[] cipherText, byte[] key, byte [] initialVector) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, InvalidParameterSpecException {
Cipher cipher = Cipher.getInstance(cipherTransformation);
SecretKeySpec secretKeySpecy = new SecretKeySpec(key, aesEncryptionAlgorithm);
IvParameterSpec ivParameterSpec = new IvParameterSpec(initialVector);
cipher.init(Cipher.DECRYPT_MODE, secretKeySpecy, ivParameterSpec);
cipherText = cipher.doFinal(cipherText);
return cipherText;
}
public byte[] encrypt(byte[] plainText, byte[] key, byte [] initialVector) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
{
Cipher cipher = Cipher.getInstance(cipherTransformation);
SecretKeySpec secretKeySpec = new SecretKeySpec(key, aesEncryptionAlgorithm);
IvParameterSpec ivParameterSpec = new IvParameterSpec(initialVector);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
plainText = cipher.doFinal(plainText);
return plainText;
}
private byte[] getKeyBytes(String key) throws UnsupportedEncodingException{
byte[] keyBytes= new byte[16];
byte[] parameterKeyBytes= key.getBytes(characterEncoding);
System.arraycopy(parameterKeyBytes, 0, keyBytes, 0, Math.min(parameterKeyBytes.length, keyBytes.length));
return keyBytes;
}
but for some data (example : u8/OgSllm2agXlDrGcdqWg== ) decryption is not working and execution catch:
javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
or for some data get different error , example : SmQ0YMiq+SHn34m8h3gWw==
get this error :
java.lang.IllegalArgumentException: bad base-64
Try with this code and download library commons-codec-1.11-bin from the below link and add it to build path
enter link description here
Java Code:
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
public class AES {
public static String encrypt(String key, String initVector, String value) {
try {
IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
byte[] encrypted = cipher.doFinal(value.getBytes());
System.out.println("encrypted string: "
+ Base64.encodeBase64String(encrypted));
return Base64.encodeBase64String(encrypted);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
public static String decrypt(String key, String initVector, String encrypted) {
try {
IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);
byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));
return new String(original);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
public static void main(String[] args) {
String key = "Bar12345Bar12345"; // 128 bit key
String initVector = "RandomInitVector"; // 16 bytes IV
System.out.println(decrypt(key, initVector,
encrypt(key, initVector, "Hello World")));
}
}
Im trying to decrypt the encrypted xml file. Im getting it as a inputstream as follows.I have the correct encrypt key. but each time my program returns empty string. Every time i enter the correct key. but each time it returns Badpadding Exception.
try{
InputStream is = new ByteArrayInputStream(decryption.getFileData().getBytes());
String xmlEncryptedStr = getStringFromInputStream(is);
String xmlStr = CipherUtils.decrypt(xmlEncryptedStr, new Long(key));
.......
here is my CipherUtils.java class
.........
public static String decrypt(String strToDecrypt,Long key)
{
String keyString=String.format("%016d", key);
//System.out.println("decrypt keyString :"+keyString);
return decrypt(strToDecrypt, keyString.getBytes());
}
public static String decrypt(String strToDecrypt,byte[] key)
{
if(strToDecrypt==null)
return strToDecrypt;
try
{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
final SecretKeySpec secretKey = new SecretKeySpec(key, "AES");
cipher.init(Cipher.DECRYPT_MODE, secretKey);
final String decryptedString = new String(cipher.doFinal(Base64.decodeBase64(strToDecrypt)));
System.out.println("CipherUtils.decryptedString :"+decryptedString);
return decryptedString;
}
catch (Exception e)
{
log.error("Ops!", e);
}
return null;
}
.......
For more information here is my encrypting code
public static String encrypt(String strToEncrypt,Long key)
{
String keyString=String.format("%016d", key);
//System.out.println("encrypt keyString :"+keyString);
return encrypt(strToEncrypt,keyString.getBytes());
}
public static String encrypt(String strToEncrypt,byte[] key)
{
if(strToEncrypt==null)
return strToEncrypt;
try
{
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
final SecretKeySpec secretKey = new SecretKeySpec(key, "AES");
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
final String encryptedString = Base64.encodeBase64String(cipher.doFinal(strToEncrypt.getBytes()));
// System.out.println("CipherUtils.encrypt :"+encryptedString);
return encryptedString;
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
I am sorry I couldn't comment so I am writing in answers section.
I faced this issue when I was using different keys though I was passing the same but i used CBC methodology.
Just to note that have you checked that encryption is also done by the AES/ECB/PKCS5Padding and not other format like AES/CBC/PKCS5Padding
Also check if key format for encryption is also having the same format like %016d of your keyValue. Also the key is 16 char long.
I created a simple AES and DESede encryption utility and it worked fine.
private static final byte[] keyValue = new String(
"CjxI&S#V&#DSA_S0dA-SDSA$").getBytes();
public static void main(String[] args) throws Exception {
Client cli = new Client();
System.out.println(cli.encrypt("your password for encryption"));
Client cli1 = new Client();
System.out.println(cli1.decrypt("fTsgVQtXvv49GynHazT4OGZ4Va1H57d+6AM+44Ex040="));
}
public String encrypt(String Data) throws Exception {
Key key = new SecretKeySpec(keyValue, "AES");
Cipher c = Cipher.getInstance("AES/ECB/PKCS5Padding");
c.init(Cipher.ENCRYPT_MODE, key);
byte[] encVal = c.doFinal(Data.getBytes());
String encryptedValue = DatatypeConverter.printBase64Binary(encVal);
// String encryptedValue = new BASE64Encoder().encode(encVal);
return encryptedValue;
}
public String decrypt(String encryptedData) throws Exception {
Key key = new SecretKeySpec(keyValue, "AES");
Cipher c = Cipher.getInstance("AES/ECB/PKCS5Padding");
c.init(Cipher.DECRYPT_MODE, key);
byte[] decordedValue = DatatypeConverter
.parseBase64Binary(encryptedData);
byte[] decValue = c.doFinal(decordedValue);
String decryptedValue = new String(decValue);
return decryptedValue;
}
I have a stringBuilder message appended with "||" symbol.(Ex: Hi||How||are||26 04 2016||finish) i have to encrypt the message and send it to the server using AES and decrypt the same at the server side. Can anyone help me out in solving this?
You can encrypt and decrypt like this:
public class AES {
public static byte[] encrypt(String key, String initVector, String value) {
try {
IvParameterSpec vector = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec secretKey = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.ENCRYPT_MODE, secretKey, vector);
byte[] encrypted = cipher.doFinal(value.getBytes());
System.out.println("encrypted string: "+ Base64.encodeBase64(encrypted));
return Base64.encodeBase64(encrypted);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
public static String decrypt(String key, String initVector, byte[] encrypted) {
try {
IvParameterSpec vector = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec secretKey = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.DECRYPT_MODE, secretKey, vector);
byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));
return new String(original);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
public static void main(String[] args) {
String key = "Foo12345Bar67890"; // 128 bit key
String initVector = "RandomInitVector"; // 16 bytes IV
StringBuilder sb = new StringBuilder("Hi||How||are||26 04 2016||finish"); //Your Text here
byte[] encryptedBytes = encrypt(key, initVector, sb.toString());
System.out.println(decrypt(key, initVector,encryptedBytes));
}
}
This is the tester:
public class CryptographySimpleTests extends ActivityTestCase
{
public void testsCryptographyClass_encryptAndDecrypt()
{
final String orgVal = "hi world! :D";
final String key = "key";
try
{
final byte[] encryptKey = Cryptography.deriveAES256Key(key);
final byte[] decryptKey = Cryptography.deriveAES256Key(key);
//Deviation method
Assert.assertTrue(Arrays.equals(encryptKey, decryptKey));
byte[] encrypted = Cryptography.encryptAES(encryptKey, orgVal.getBytes());
Assert.assertFalse(Arrays.equals(encrypted, orgVal.getBytes()));
byte[] decrypted = Cryptography.decryptAES(decryptKey, encrypted);
Assert.assertTrue(Arrays.equals(orgVal.getBytes(), decrypted));
}
catch (Exception e) {
Assert.fail(e.getMessage());
}
}
}
Which fails because of the last assert:
Assert.fail(e.getMessage());
When trying to execute:
byte[] decrypted = Cryptography.decryptAES(decryptKey, encrypted);
Gives this stack trace:
javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
at com.android.org.conscrypt.NativeCrypto.EVP_CipherFinal_ex(Native Method)
at com.android.org.conscrypt.OpenSSLCipher.doFinalInternal(OpenSSLCipher.java:430)
at com.android.org.conscrypt.OpenSSLCipher.engineDoFinal(OpenSSLCipher.java:466)
at javax.crypto.Cipher.doFinal(Cipher.java:1340)
at bdevel.encuentralo.utils.Cryptography.decryptAES(Cryptography.java:59)
at bdevel.encuentralo.CryptographySimpleTests.testsCryptographyClass_encryptAndDecrypt(CryptographySimpleTests.java:32)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
at junit.framework.TestCase.runBare(TestCase.java:134)
at junit.framework.TestResult$1.protect(TestResult.java:115)
at junit.framework.TestResult.runProtected(TestResult.java:133)
at junit.framework.TestResult.run(TestResult.java:118)
at junit.framework.TestCase.run(TestCase.java:124)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1837)
These are my functions:
public class Cryptography {
/**
* #param key AES Key
* #param inputValue Data to encrypt
* #return Can return null if something goes wrong
*/
public static byte[] encryptAES(byte[] key, byte[] inputValue)
throws NoSuchPaddingException, BadPaddingException, IllegalBlockSizeException
{
SecretKeySpec sKeyS = new SecretKeySpec(key, "AES");
Cipher cipher = null;
try {
cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, sKeyS);
}
catch (NoSuchAlgorithmException | InvalidKeyException i) {
cipher = null;
}
return cipher != null ? cipher.doFinal(inputValue) : null;
}
public static byte[] decryptAES(byte[] key, byte[] encryptedData)
throws NoSuchPaddingException, BadPaddingException, IllegalBlockSizeException
{
SecretKeySpec sKeyS = new SecretKeySpec(key, "AES");
Cipher cipher = null;
try {
cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, sKeyS);
}
catch (NoSuchAlgorithmException | InvalidKeyException i) {
cipher = null;
}
return cipher != null ? cipher.doFinal(encryptedData) : null;
}
private static byte[] deriveAES256KeySalt = null;
public static byte[] deriveAES256Key(String password)
throws InvalidKeySpecException, NoSuchAlgorithmException
{
/* Store these things on disk used to derive key later: */
int iterationCount = 1000;
int saltLength = 32; // bytes; should be the same size as the output (256 / 8 = 32)
int keyLength = 256; // 256-bits for AES-256, 128-bits for AES-128, etc
/* When first creating the key, obtain a salt with this: */
if(deriveAES256KeySalt == null) {
SecureRandom random = new SecureRandom();
deriveAES256KeySalt = new byte[saltLength];
random.nextBytes(deriveAES256KeySalt);
}
/* Use this to derive the key from the password: */
KeySpec keySpec = new PBEKeySpec(password.toCharArray(), deriveAES256KeySalt, iterationCount, keyLength);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();
return keyBytes;
}
}
If the assert that checks if the keys are the same works, why do I get that exception?
You are eating an java.security.InvalidKeyException: Illegal key size or default parameters exception in your encryptAES and decryptAES methods. So don't eat them, either declare as throws or promote to RuntimeException.
Turns out you have two problems, for this reason, you can't do 256, but 128 solves that, then you are also requesting CBC without an IvParameterSpec (Which is causing java.security.InvalidKeyException: Parameters missing). So supply that or change to ECB:
public static byte[] encryptAES(byte[] key, byte[] inputValue)
throws NoSuchPaddingException, BadPaddingException, IllegalBlockSizeException, NoSuchAlgorithmException, InvalidKeyException {
SecretKeySpec sKeyS = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, sKeyS);
return cipher.doFinal(inputValue);
}
public static byte[] decryptAES(byte[] key, byte[] encryptedData)
throws NoSuchPaddingException, BadPaddingException, IllegalBlockSizeException, NoSuchAlgorithmException, InvalidKeyException {
SecretKeySpec sKeyS = new SecretKeySpec(key, "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, sKeyS);
return cipher.doFinal(encryptedData);
}
Key length:
public static byte[] deriveAES256Key(String password)
throws InvalidKeySpecException, NoSuchAlgorithmException {
...
int keyLength = 128; // 256-bits for AES-256, 128-bits for AES
...
So I got it working like that, but step one is to stop eating the exception and you'll get better clues and probably work out on own.
I'm using CBC without an IvParameterSpec.
It was solved adding the following to encrypt and decrypt:
cipher.init(Cipher."mode here", sKeyS, getIvSpecAES256());
Where "getIvSpecAES256()" return the same value always.
I have algorithm of encryption\ decryption files:
private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = new SecureRandom();
sr.setSeed(seed);
kgen.init(sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
It works great, but on Android 4.4 (api 19) I have strangely exception
javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
What is it?
Here what I got: http://www.logikdev.com/2010/11/01/encrypt-with-php-decrypt-with-java/
public class AES2 {
private static final String TRANSFORMATION = "AES/CFB8/NoPadding";
private static final String ALGO_MD5 = "MD5";
private static final String ALGO_AES = "AES";
/**
* See http://www.logikdev.com/2012/12/12/md5-generates-31-bytes-instead-of-32/ form more detail.
*
* #param input
* #return
* #throws NoSuchAlgorithmException
*/
private static String md5(String input) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance(ALGO_MD5);
byte[] messageDigest = md.digest(input.getBytes());
BigInteger number = new BigInteger(1, messageDigest);
return String.format("%032x", number);
}
public static String decrypt(String encryptedData, String initialVectorString, String secretKey) {
String decryptedData = null;
try {
String md5Key = md5(secretKey);
SecretKeySpec skeySpec = new SecretKeySpec(md5Key.getBytes(), ALGO_AES);
IvParameterSpec initialVector = new IvParameterSpec(initialVectorString.getBytes());
Cipher cipher = Cipher.getInstance(TRANSFORMATION);
cipher.init(Cipher.DECRYPT_MODE, skeySpec, initialVector);
byte[] encryptedByteArray = Base64.decode(encryptedData.getBytes(), Base64.DEFAULT);
byte[] decryptedByteArray = cipher.doFinal(encryptedByteArray);
decryptedData = new String(decryptedByteArray);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return decryptedData;
}
}
So you have to create a initialVectorString (example: "fedcba9876543210"). Hope this help.