(OOC - That's right. The ships, and even individual accounts, have their information encoded on secured computers. However, the transaction data is still x-boated for comparison sake, in case the local computers were tampered with, or an error is made. And yes, it takes weeks or months. That's why the Imperium's currency is insured by the Imperium, so that faith in it can be maintained. A local merchant knows that even if he's paid with credits that come from an account that is already empty, he won't get the short end of the stick. But you're right in that the Zax has a "black box" computer who's sole purpose is to track its finances, and was inspected and sealed by financial officers trained to do so. Every time the ship undergoes a refit or major servicing, the computer is checked again and resealed. Similarly, Zoe, and each of us, have an official issue Imperium credit chit, or card, that tracks our finances. Tampering with it isn't impossible, but it's highly illegal, and the data is heavily encrypted. And so on...)