Quote from: SPC_Bitcoin on October 30, 2013, 01:09:53 AM

Quote from: tonto on October 28, 2013, 08:19:11 PM

I would be interested if:

1. the card never asked for any identifying information. So like a standard gift card, but pre-registered, turn-key
2. I could use it for either credit/debit purchase and/or ATM withdrawals
3. There was no fraud-detection protection built in. It's swipe and go. I wouldn't want to get annoying calls saying "the fraud detection unit thinks your purchase of 100 Thai whores isn't a legit purchase, please confirm or deny so we know if we need to cancel the card."
4. No limit (or a very high limit), nothing retarded like $500

Exactly!

captured the essence of bitcoin usability and function.

I was pondering my ideal bitcoin Visa card recently. Why can't we have a dynamic limit? Here's what I'm thinking: the user transfers coins in such a way that *either* the credit card provider or the user can spend them.

Consider the case where I want to buy an expensive all-inclusive trip to Bora Bora. I send the required BTC to some shared address, wait, say, 3 confirms, and then order my trip online. When the website seeks authorization for my purchase, the credit card provider approves the purchase and immediately transfer the coins to their private address.

Now consider the case where I decided at the last minute not to make the trip and I want to get my bitcoins back [without making annoying phone calls, etc]. Since I too have authority, I simple transfer these coins back to one of my privately controlled addresses.

The only potential problem I see is if the user somehow transfers the coins to their private address at the same time as the credit card provider [effectively a double spend]. But maybe with enough of a delay in the authorization (the credit card provider can see that most of the network has picked up the honest transfer and no double spend was detected) or some other trick we could prevent this.

Perhaps my implementation could use some tweaking. But what I'm trying to achieve is (1) dynamic limits, (2) make it easy and quick to reliably get your unspent coins back.