Simple two-way encryption for C#

Simple AES

 using System;  
 using System.Data;  
 using System.Security.Cryptography;  
 using System.IO;  
 public class SimpleAES  
 {  
   // Change these keys  
   private byte[] Key = { 123, 217, 19, 11, 24, 26, 85, 45, 114, 184, 27, 162, 37, 112, 222, 209, 241, 24, 175, 144, 173, 53, 196, 29, 24, 26, 17, 218, 131, 236, 53, 209 };  
   private byte[] Vector = { 146, 64, 191, 111, 23, 3, 113, 119, 231, 121, 2521, 112, 79, 32, 114, 156 };  
   private ICryptoTransform EncryptorTransform, DecryptorTransform;  
   private System.Text.UTF8Encoding UTFEncoder;  
   public SimpleAES()  
   {  
     //This is our encryption method  
     RijndaelManaged rm = new RijndaelManaged();  
     //Create an encryptor and a decryptor using our encryption method, key, and vector.  
     EncryptorTransform = rm.CreateEncryptor(this.Key, this.Vector);  
     DecryptorTransform = rm.CreateDecryptor(this.Key, this.Vector);  
     //Used to translate bytes to text and vice versa  
     UTFEncoder = new System.Text.UTF8Encoding();  
   }  
   /// -------------- Two Utility Methods (not used but may be useful) -----------  
   /// Generates an encryption key.  
   static public byte[] GenerateEncryptionKey()  
   {  
     //Generate a Key.  
     RijndaelManaged rm = new RijndaelManaged();  
     rm.GenerateKey();  
     return rm.Key;  
   }  
   /// Generates a unique encryption vector  
   static public byte[] GenerateEncryptionVector()  
   {  
     //Generate a Vector  
     RijndaelManaged rm = new RijndaelManaged();  
     rm.GenerateIV();  
     return rm.IV;  
   }  
   /// ----------- The commonly used methods ------------------------------    
   /// Encrypt some text and return a string suitable for passing in a URL.  
   public string EncryptToString(string TextValue)  
   {  
     return ByteArrToString(Encrypt(TextValue));  
   }  
   /// Encrypt some text and return an encrypted byte array.  
   public byte[] Encrypt(string TextValue)  
   {  
     //Translates our text value into a byte array.  
     Byte[] bytes = UTFEncoder.GetBytes(TextValue);  
     //Used to stream the data in and out of the CryptoStream.  
     MemoryStream memoryStream = new MemoryStream();  
     /*  
      * We will have to write the unencrypted bytes to the stream,  
      * then read the encrypted result back from the stream.  
      */  
     #region Write the decrypted value to the encryption stream  
     CryptoStream cs = new CryptoStream(memoryStream, EncryptorTransform, CryptoStreamMode.Write);  
     cs.Write(bytes, 0, bytes.Length);  
     cs.FlushFinalBlock();  
     #endregion  
     #region Read encrypted value back out of the stream  
     memoryStream.Position = 0;  
     byte[] encrypted = new byte[memoryStream.Length];  
     memoryStream.Read(encrypted, 0, encrypted.Length);  
     #endregion  
     //Clean up.  
     cs.Close();  
     memoryStream.Close();  
     return encrypted;  
   }  
   /// The other side: Decryption methods  
   public string DecryptString(string EncryptedString)  
   {  
     return Decrypt(StrToByteArray(EncryptedString));  
   }  
   /// Decryption when working with byte arrays.    
   public string Decrypt(byte[] EncryptedValue)  
   {  
     #region Write the encrypted value to the decryption stream  
     MemoryStream encryptedStream = new MemoryStream();  
     CryptoStream decryptStream = new CryptoStream(encryptedStream, DecryptorTransform, CryptoStreamMode.Write);  
     decryptStream.Write(EncryptedValue, 0, EncryptedValue.Length);  
     decryptStream.FlushFinalBlock();  
     #endregion  
     #region Read the decrypted value from the stream.  
     encryptedStream.Position = 0;  
     Byte[] decryptedBytes = new Byte[encryptedStream.Length];  
     encryptedStream.Read(decryptedBytes, 0, decryptedBytes.Length);  
     encryptedStream.Close();  
     #endregion  
     return UTFEncoder.GetString(decryptedBytes);  
   }  
   /// Convert a string to a byte array. NOTE: Normally we'd create a Byte Array from a string using an ASCII encoding (like so).  
   //   System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();  
   //   return encoding.GetBytes(str);  
   // However, this results in character values that cannot be passed in a URL. So, instead, I just  
   // lay out all of the byte values in a long string of numbers (three per - must pad numbers less than 100).  
   public byte[] StrToByteArray(string str)  
   {  
     if (str.Length == 0)  
       throw new Exception("Invalid string value in StrToByteArray");  
     byte val;  
     byte[] byteArr = new byte[str.Length / 3];  
     int i = 0;  
     int j = 0;  
     do  
     {  
       val = byte.Parse(str.Substring(i, 3));  
       byteArr[j++] = val;  
       i += 3;  
     }  
     while (i < str.Length);  
     return byteArr;  
   }  
   // Same comment as above. Normally the conversion would use an ASCII encoding in the other direction:  
   //   System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();  
   //   return enc.GetString(byteArr);    
   public string ByteArrToString(byte[] byteArr)  
   {  
     byte val;  
     string tempStr = "";  
     for (int i = 0; i <= byteArr.GetUpperBound(0); i++)  
     {  
       val = byteArr[i];  
       if (val < (byte)10)  
         tempStr += "00" + val.ToString();  
       else if (val < (byte)100)  
         tempStr += "0" + val.ToString();  
       else  
         tempStr += val.ToString();  
     }  
     return tempStr;  
   }  
 }