[C#] RenderHash() - String Extension for generating a (SHA1) hash

RenderHash.cs

        /// <summary>
        /// Generates a (SHA1) hashed string, by using the passphrase as a poor man's salt.
        /// </summary>
        /// <param name="orderReference">(Optional) This reference is used for storing a (temporary) shipping order. You can decide for yourself which reference to use, but it needs to be unique. The reference is used for identifying the shipping order in the Paazl database.</param>
        public static string RenderHash(this string value, string passPhrase)
        {
            // Append the passphrase to the value
            value += passPhrase;

            // Convert the string value to a byte array 
            // Note: I've used the UTF8 encoding here
            byte[] buffer = Encoding.UTF8.GetBytes(value);

            // And automagically convert it to a hashed string
            SHA1CryptoServiceProvider cryptoTransformSHA1 = new SHA1CryptoServiceProvider();
            string hash = BitConverter.ToString(cryptoTransformSHA1.ComputeHash(buffer)).Replace("-", "");

            return hash;
        }