using System;

using System.Security.Cryptography;

using System.Text;

public class Program

{

    public void Main()

    {

        string key = EncryptData("Hello World", "Lorem ipsum dolor sit amet, cons");

        Console.WriteLine(key);

        string akey = DecryptData("wgXgIU9XSBFYjJTo6qPc4Q==", "Lorem ipsum dolor sit amet, cons");

        // Console.WriteLine(akey);

    }

    public string EncryptData(string textData, string Encryptionkey)  

        {  

            RijndaelManaged objrij = new RijndaelManaged();  

            //set the mode for operation of the algorithm   

            objrij.Mode = CipherMode.CBC;  

            //set the padding mode used in the algorithm.   

            objrij.Padding = PaddingMode.PKCS7;  

            //set the size, in bits, for the secret key.   

            objrij.KeySize = 0x80;  

            //set the block size in bits for the cryptographic operation.    

            objrij.BlockSize = 0x80;  

            //set the symmetric key that is used for encryption & decryption.    

            byte[] passBytes = Encoding.UTF8.GetBytes(Encryptionkey);

            //set the initialization vector (IV) for the symmetric algorithm    

            byte[] EncryptionkeyBytes = new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

            int len = passBytes.Length;

            if (len > EncryptionkeyBytes.Length)  

            {  

                len = EncryptionkeyBytes.Length;  

            }  

            Array.Copy(passBytes, EncryptionkeyBytes, len);  

            objrij.Key = EncryptionkeyBytes;  

            objrij.IV = EncryptionkeyBytes;  

            //Creates a symmetric AES object with the current key and initialization vector IV.    

            ICryptoTransform objtransform = objrij.CreateEncryptor();  

            byte[] textDataByte = Encoding.UTF8.GetBytes(textData);  

            //Final transform the test string.  

            return Convert.ToBase64String(objtransform.TransformFinalBlock(textDataByte, 0, textDataByte.Length));  

        } 

    string DecryptData(string EncryptedText, string Encryptionkey)  

            {  

                RijndaelManaged objrij = new RijndaelManaged();  

                objrij.Mode = CipherMode.CBC;  

                objrij.Padding = PaddingMode.PKCS7;  

                objrij.KeySize = 0x80;  

                objrij.BlockSize = 0x80;  

                byte[] encryptedTextByte = Convert.FromBase64String(EncryptedText);  

                byte[] passBytes = Encoding.UTF8.GetBytes(Encryptionkey);  

                byte[] EncryptionkeyBytes = new byte[0x10];  

                int len = passBytes.Length;  

                if (len > EncryptionkeyBytes.Length)  

                {  

                    len = EncryptionkeyBytes.Length;  

                }  

                Array.Copy(passBytes, EncryptionkeyBytes, len);  

                objrij.Key = EncryptionkeyBytes;  

                objrij.IV = EncryptionkeyBytes;  

                byte[] TextByte = objrij.CreateDecryptor().TransformFinalBlock(encryptedTextByte, 0, encryptedTextByte.Length);  

                return Encoding.UTF8.GetString(TextByte);  //it will return readable string  

            }   

​

}