How To Encrypt And Decrypt In C# Using Simple AES Keys

Thus the messages can be easily encrypted and decrypted.

Ok, now coming to the C# coding part, the Source code of encryption and decryption for one-way communication is given below,

Encryption in C#

Here I have taken a string with the value "Water" to encrypt

I had taken "Santhosh" as the public key and "engineer" as a secret key and here I had got the encrypted value as "VtbM/yjSA2Q="

public string Encrypt()
{
    try
    {
        string textToEncrypt = "Water";
        string ToReturn = "";
        string publickey = "santhosh";
        string secretkey = "engineer";
        byte[] secretkeyByte = {};
        secretkeyByte = System.Text.Encoding.UTF8.GetBytes(secretkey);
        byte[] publickeybyte = {};
        publickeybyte = System.Text.Encoding.UTF8.GetBytes(publickey);
        MemoryStream ms = null;
        CryptoStream cs = null;
        byte[] inputbyteArray = System.Text.Encoding.UTF8.GetBytes(textToEncrypt);
        using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
        {
            ms = new MemoryStream();
            cs = new CryptoStream(ms, des.CreateEncryptor(publickeybyte, secretkeyByte), CryptoStreamMode.Write);
            cs.Write(inputbyteArray, 0, inputbyteArray.Length);
            cs.FlushFinalBlock();
            ToReturn = Convert.ToBase64String(ms.ToArray());
        }
        return ToReturn;
    }
    catch (Exception ex)
    {
        throw new Exception(ex.Message, ex.InnerException);
    }
}

Decryption in C#

After encrypting the value "Water", I got the encrypted value "VtbM/yjSA2Q=" which now will be decrypted back to "Water"

public string Decrypt()
{
    try
    {
        string textToDecrypt = "VtbM/yjSA2Q=";
        string ToReturn = "";
        string publickey = "santhosh";
        string privatekey = "engineer";
        byte[] privatekeyByte = System.Text.Encoding.UTF8.GetBytes(privatekey);
        byte[] publickeybyte = System.Text.Encoding.UTF8.GetBytes(publickey);
        MemoryStream ms = null;
        CryptoStream cs = null;
        byte[] inputbyteArray = new byte[textToDecrypt.Replace(" ", "+").Length];
        inputbyteArray = Convert.FromBase64String(textToDecrypt.Replace(" ", "+"));
        using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
        {
            ms = new MemoryStream();
            cs = new CryptoStream(ms, des.CreateDecryptor(publickeybyte, privatekeyByte), CryptoStreamMode.Write);
            cs.Write(inputbyteArray, 0, inputbyteArray.Length);
            cs.FlushFinalBlock();
            Encoding encoding = Encoding.UTF8;
            ToReturn = encoding.GetString(ms.ToArray());
        }
        return ToReturn;
    }
    catch (Exception ae)
    {
        throw new Exception(ae.Message, ae.InnerException);
    }
}

By using these two methods we can encrypt and decrypt the string in C#. One should note that the key size of the public key and private key should be equal and should not exceed less than 8 characters as I had encoded using UTF8.

Thanks for reading the article.

All the best for your future endeavors!