writing checks

newsham (OP)

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writing checks

January 10, 2011, 03:21:43 AM

#1

Since bitcoin transactions can be crafted offline (away from the bitcoin network), why not standardize a bitcoin transaction file (or URI)? My proposal:

- Standard format for a file containing a proposed bitcoin transaction
- standard client could generate a transaction file, even when offline.
- simple clients could generate transaction files if they had access to the wallet
- there would need to be a record of coins that were promised to others and not yet used
- when the transaction is finally posted, the record can be discarded
- the user could reclaim the coin by spending it himself before the transaction file
is used, ie. by giving himself the coin and registering that transaction on the bitcoin network
- standard client could consume this file and post the transaction to the bitcoin network
and confirm that the transaction took place, or alert the user that it did not.
- Online services that would allow you to post a transaction
- would receive transaction files and post them to the bitcoin network
- would allow a device without bitcoin clients of their own to "cash" a check
- could be a simple web app that backends to bitcoind. probably a few hundred lines of a scripting language
- would be handy to allow users to verify previous transactions in this way too
- A standard URI that encapsulate the transaction file
- cell phone apps could register to handle this URI, and post them to bitcoin network directly
or use an online web service to post the transaction.
- cell phone app could generate QR codes for a wallet, without participating in the bitcoin network.

am I missing anything obvious?
This seems like it would be a big win, being able to email around bitcoin "checks" and
being able to do phone-to-phone transactions with a simple QR.

-Tim

newsham (OP)

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Re: writing checks

January 10, 2011, 03:57:43 AM

#2

A flaw.. when spending a coin, your TX sends some of it to the recipient and makes change for yourself.
If you want to spend a 20BTC coin with two checks, the two checks would either interfere with each
other or one would only be valid after the other transaction is submitted. So.. this is not as simple
and elegant as I first thought.. you would want to "make exact change" online somehow before writing
checks.. which means you have to at least be partially online.. one advantage that remains, you could
use an online TX submission service to make change, and you wouldn't have to trust the service.

*sigh* oh well...

-Tim

Details, scenerio 1:
start with 20BTC
write check for 15 BTC to friend, with 5BTC back to yourself. TX1.
write check for 5 BTC to another friend (no change). TX2
TX2 is not valid until after TX1 is submitted.

scenerio 2:
start with 20BTC
write check for 15 BTC to friend, with 5BTC back to yourself. TX1
write check for 5 BTC to another friend with same original 20BTC, with 15BTC back to yourself, TX2.
Only one of TX1 or TX2 can be submitted. The second will fail.

FreddyFender

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Shamantastic!

Re: writing checks

January 10, 2011, 05:23:51 AM

#3

Hey Tim,
Not sure of your current skillz in coding, but you may find a perfect opportunity with:

https://github.com/FellowTraveler/Open-Transactions

Looks like it may be of value to eventually tie bitcoin and OT together along with future APIs of BitX.
Much of what your asking about and lots of code is located there.

For more info, refer to these threads:

http://bitcointalk.org/index.php?topic=2299.0
Exploiting Special Properties of Bitcoin For Uses Other Than Currency

http://bitcointalk.org/index.php?topic=1790.0
BitDNS and Generalizing Bitcoin ***This is a good one***

These new `currencies` would need a new checking account style application to record valuation and bitcoin may become father to many new applications.
Open-Transaction would be repository for all the APIs associated with bitcoin.

Let me know what you think.

http://slightlyoffended.blogspot.ca/

Local

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Re: writing checks

January 10, 2011, 07:40:40 AM

#4

Quote from: newsham on January 10, 2011, 03:57:43 AM

A flaw.. when spending a coin, your TX sends some of it to the recipient and makes change for yourself.
If you want to spend a 20BTC coin with two checks, the two checks would either interfere with each
other or one would only be valid after the other transaction is submitted. So.. this is not as simple
and elegant as I first thought.. you would want to "make exact change" online somehow before writing
checks.. which means you have to at least be partially online.. one advantage that remains, you could
use an online TX submission service to make change, and you wouldn't have to trust the service.

*sigh* oh well...

-Tim

Details, scenerio 1:
start with 20BTC
write check for 15 BTC to friend, with 5BTC back to yourself. TX1.
write check for 5 BTC to another friend (no change). TX2
TX2 is not valid until after TX1 is submitted.

scenerio 2:
start with 20BTC
write check for 15 BTC to friend, with 5BTC back to yourself. TX1
write check for 5 BTC to another friend with same original 20BTC, with 15BTC back to yourself, TX2.
Only one of TX1 or TX2 can be submitted. The second will fail.

Could this be solved by prepping addresses to have the correct amounts so that there will be no change?

newsham (OP)

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Re: writing checks

January 10, 2011, 05:10:02 PM

#5

Quote from: Local on January 10, 2011, 07:40:40 AM

Could this be solved by prepping addresses to have the correct amounts so that there will be no change?

Can you explain further? If you mean that right before you make a payment you
make some change for yourself, that was what I was suggesting in my previous
message. If you mean something else, let me know

-Tim

Local

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Re: writing checks

January 10, 2011, 10:18:31 PM

#6

Quote from: newsham on January 10, 2011, 05:10:02 PM

Quote from: Local on January 10, 2011, 07:40:40 AM

Could this be solved by prepping addresses to have the correct amounts so that there will be no change?

Can you explain further? If you mean that right before you make a payment you
make some change for yourself, that was what I was suggesting in my previous
message. If you mean something else, let me know

-Tim

Ah, sorry, I didn't see that at first. I think we do mean the same thing. And now I realize that it kind of defeats the point.