private static string Decrypt(string encryptedText, string encryptionKey, string salt) { if (string.IsNullOrEmpty(encryptedText)) { return(null); } if (string.IsNullOrEmpty(encryptionKey)) { throw new ArgumentNullException(nameof(encryptionKey)); } if (string.IsNullOrEmpty(salt)) { throw new ArgumentNullException(nameof(salt)); } return(RijndaelSimple.SHA1Decrypt(encryptedText, encryptionKey, salt, IV)); }