C AES encrypts strings

C# AES Encrypt the string

public class AESHelper
{
    
    /// <summary>
    /// AES Encrypted key   Must be 32 position 
    /// </summary>
    public static string keyValue = "12345678123456781234567812345678";

    /// <summary>
    /// AES  Algorithm encryption 
    /// </summary>
    /// <param name="content"> Plaintext </param>
    /// <param name="Key"> secret key </param>
    /// <returns> Encrypted ciphertext </returns>
    public static string Encrypt(string content, string Key)
    {
    
        try
        {
    
            byte[] keyBytes = Encoding.UTF8.GetBytes(Key);

            RijndaelManaged rDel = new RijndaelManaged();

            rDel.Key = keyBytes;

            rDel.Mode = CipherMode.ECB;

            rDel.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = rDel.CreateEncryptor();

            byte[] contentBytes = Encoding.UTF8.GetBytes(content);

            byte[] resultBytes = cTransform.TransformFinalBlock(contentBytes, 0, contentBytes.Length);

            string result = Convert.ToBase64String(resultBytes, 0, resultBytes.Length);

            return result;
        }
        catch (Exception ex)
        {
    
            UnityEngine.Debug.LogError(" Encryption error ：" + ex.ToString());

            return null;
        }
    }

    /// <summary>
    /// AES  Algorithm decryption 
    /// </summary>
    /// <param name="content"></param>
    /// <param name="key"></param>
    /// <returns></returns>
    public static string Decipher(string content, string key)
    {
    
        try
        {
    
            byte[] keyBytes = Encoding.UTF8.GetBytes(key);

            RijndaelManaged rm = new RijndaelManaged();

            rm.Key = keyBytes;

            rm.Mode = CipherMode.ECB;

            rm.Padding = PaddingMode.PKCS7;

            ICryptoTransform ict = rm.CreateDecryptor();

            byte[] contentBytes = Convert.FromBase64String(content);

            byte[] resultBytes = ict.TransformFinalBlock(contentBytes, 0, contentBytes.Length);

            return Encoding.UTF8.GetString(resultBytes);
        }
        catch (Exception ex)
        {
    
            UnityEngine.Debug.LogError(" Decryption error ：" + ex.ToString());

            return null;
        }
    }
}