FirstData E4: store.authorization can be

TransArmor tokenization requests store only the card number. Future requests must pass in the brand, name, and expiration date. This change serializes all required information into the response's authorization parameter, which then can be passed directly into subsequent authorization or purchase transactions instead of the CreditCard instance.

We are still using v11 of the API. The previous unqualified API URL actually uses version 8. v12 is not backwards-compatible with the existing gateway implementation, as it _requires_ additional authentication credentials for it's mandatory HMAC feature. An upgrade to v12 would require a creating separate gateway class to not break backwards compatibility.