/// <summary>
        /// Converts a string to its MD5 equivalent - this is used for verification in the header of messages to openSrs
        /// </summary>
        private string ToMd5String(string value)
        {
            var hash = CryptographyHelper.CalculateMD5Hash(value);

            return(!String.IsNullOrEmpty(hash) ? hash.ToLower() : string.Empty);
        }