DeeLoaf

Use case for inter network trading in the simplest way I can imagine that could work

Bob is a member of The Warehouse Network (TWN)
Bob spends most of his days overseeing canning machinery at a local soup canning facility.
Bob prefers to be paid for his work in KJ currency offered by TWN.

Alice is a member of Farmers United (FU)
Alice spends most of her days overseeing fieldwork machinery at a local permaculture farm
Alice prefers to be paid in Human Hours of Work (HOW) currency offered by FU.

Alice needs some finished manufactured goods for personal needs. She goes down to the nearest BigBoxMart (storefronts operated by TWN). Everything in BigBoxMart is priced in TWH-KJ currency.
Fortunately for Alice there is a pre-existing relationship between FU and TWH.
Lets throw this out there: when 2 networks establish a relationship, or a link, the link should follow some standard protocol.
- each end of the link must specify the currency being used by the partner on that end
so for a link between TWN and FU lets say
TWN is going to be holding the inter-network account in KJ
FU is going to be holding the inter-network account in HOW.

Alice wants a can of soup from TWH. At the checkout, Alice needs only to have an account with a recognized trading network. If she does not have an account with a recognized network she can choose to open an account with TWH or link to her home network through GETS (_everyone_ is linked to GETS, and a few other different international clearing houses as well though GETS is the most popular and therefor the defacto), for the usual fee (GETS charges a small fee for taking on the liability when parties who dont know/trust each other use it to trade with each other).
So anyway Alice is a member of FU and TWH recognizes FU so the transaction goes like this:
The exchange rate* that will be used for this transaction is determined and must be agreed upon by parties of tx. (otherwise stop tx right now)
TWH will ask FU for Alice's public key.
TWH will ask Alice to sign a message stating the exchange of resources (can of soup to Alice in exchange for KJ value)
TWH will verify the signature Alice placed on the tx message.
TWH will communicate to FU using the standard protocol** that Alices account must be reduced by the agreed upon exchanged value. (computed in HOW for FU side entries)

On the TWH side, this transaction will move KJ out of the TWH<->FU account and into the BigBoxMart management account. (note all tx pushed through the till will either remove funds from particular TWH member account or from a inter-network account, and transferred to BigBoxMart management account)
On the FU side, this transaction will move HOW out of Alices FU account and into the FU<->TWH account.

* exhange rate is readily computable using a variety of means that will all yield some very similar result. My proposed method is to identify a basket of commodity type or comparable goods between two networks and compute their value on each side in each networks exchange currency. The difference in value of the two baskets will then determine a usable exchange rate.
**the OpenTransact protocol with a few small extensions to deal with real world problems, likely including the value of the tx in the agreed values of both inter-network exchange currencies

I _think_ this should address the problem of how networks inter trade. Really this is just an extension to OpenTransaction protocol which someone has already created.

Please identify flaws with this and propose your method of attack, so I can propose solutions to your imagined problems and countermeasures to your attacks!