Digital Currency [OT]

Ryan Simpkins plug at
Mon Jul 2 12:28:23 MDT 2007

On Mon, July 2, 2007 11:39, Jonathan Ellis wrote:
> On 7/2/07, Michael L Torrie <torriem at> wrote:
>> On Mon, 2007-07-02 at 13:27 -0400, Jonathan Ellis wrote:
>> > The important thing is the concept of digital *cash* that, like paper
>> > cash, would be anonymous but secure.
>> Not going to ever happen, in my opinion.  The current system works very
>> well (Visa, Bank card networks), and the idea of allowing anonymous
>> digital transactions is not something that any country in the world is
>> keen to allow these days.
> That's why it's called science _fiction._ :)

I'm not much of a geek I guess, I haven't read this book. However, if I were
to design an anonymous digital currency system here is what I would make up:

 ## The Device ##
There will need to be some device you carry that contains the currency. Since
this is the fictional future this device is super-secure. Any attempt at
modifying the device will result in it's destruction. One can imagine that
this device has some way to send, approve, and receive transactions from other
similar devices. Voice recognition? Check. Fancy lights and futuristic noises?
Check. Super small size? Check. Amazingly powerful mobile computer with
unlimited battery life? Check. Gazillions of bytes of storage? Check.

We will call such a device a digital wallet. To make it simple for discussion
purposes picture a digital wallet about the size of a bill fold, which would
fit easily in your pocket. Of course, the bigger the wallet the more memory,
so you can carry around more currency...

  ## The Currency ##
Each lowest measure of currency (we can call it a credit) will need to have a
totally unique identifying number. In a world where there are potentially many
quadrillions of credits, this is going to be a big unique number. The issuing
authority (government) assigns these numbers. If two similar credit IDs show
up in the global digital currency system, fraud has occurred. In fact, a
unique number *is* a credit. So, if I owe you 100 credits, I need to send 100
unique numbers from my device to yours. I don't have the ability to make up
unique numbers because doing so would destroy my digital wallet, and
eventually alert the authorities to fraud.

  ## The System ##
In order for transactions to be anonymous the credit carrying devices must not
have any identification methods - except to other authorized devices. However,
that doesn't mean it can't communicate to a global network, or a local ad-hoc
network. This is helpful, for example, when you are "off-world" and loose a
bet to some alien species. He wants to be paid and he isn't going to wait to
get back to the network to get his money. You need to send your credits from
your device to his. Again, this shouldn't be an issue if the device is as
secure as it needs to be. Two or more digital wallets can create an ad-hoc
network based on proximity to other devices.

  ## The Reserve ##
I imagine there will be some big gigantic federal reserve system that will act
as a digital clearing house: accepting credits, issuing credits, transferring
credits to other currency forms, checking for fraud, etc. So, occasionally,
these devices need to trickle up to that system (via banks or something
similar). Also, this federal reserve system is responsible for creating new
digital wallets so they can ensure the credits remain secure. You don't want
just anyone making them. You want to deny connections to another unauthorized

Here is an example of how I could picture it working:
1) Go to your local futuristic Zions bank.
2) Pick up an empty 'digital wallet' from the counter.
3) Go to the ATM/Kiosk and the proximity detectors will identify your digital
wallet as empty. Your digital wallet glows green to indicate it is in a
'loading zone' and has a secure connection to the ATM. If you have two or more
wallets, you will need to select which one you want to put money in.
4) Wave your hand with the embedded microchip or whatever over the ATM to
authenticate yourself.
5) Tell the ATM (voice recognition of course) you want to load 5 mega credits
on to the wallet.
6) The ATM contacts the universal federal authority and loads 5 bazillion
unique numbers on your wallet. You never see these numbers, all you see is the
quantity of credits (5 Mega) show up on you digital wallet readout screen
7) You now have a device containing some of 'your' credits. If you loose it,
or give it to someone else, they own the credits. Don't spend them all in once

So you wanna buy that gold watch from the Teliaxian Face Dancer on Gedes
Prime. Well, there are no federal networks around. What do you do?
1) Put your wallet in to 'send this guy some money' mode.
2) The face dancer puts its wallet in 'get some money' mode.
3) You say '100 Credits' and the device gets ready to transfer
4) Wave the two digital wallets near each other, and in an instant a secure
transaction transfers the unique numbers from your wallet to the face dancers.
5) Suddenly space pirates show up, take all the wallets... and the watch. Too
bad. Maybe some day they'll design a system that ties your ID to the credits
so people can't steal them...

So - there is some fiction for you! Now you geeks go out and design it. I want
a digital wallet I can talk to.


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