Bitcoin wallet on memory card

[unclescrooge]

Bitcoin wallet on memory card
Or how to get bitcoins to the physical world without smartphones or bank-like third parties.

Hello everyone,

To bring bitcoins to the physical world, we need a system that is largely available and cheap (exit the smartphones), and that keep the bitcoins spirit (no third parties involved in transactions) to make it resilient against States predation.

Bitcoin bills are a way to do this, but I've not been convinced by the security and the usability, and anyway I find credit card much more convenient.

So, here's my proposal:

You host your wallet on a memory chip card (or whatever) that you can carry around with you
When you wanna buy something, you insert the card into the vendor reader. This reader is connected to a computer on wich a special software is running. The software, when a wallet.dat in a memory card pops in, run a bitcoind instance with this wallet, to send the agreed amount.
For security, the user has to enter is passphrase (much like he would enter a PIN with a credit card). The bitcoins are sent. No need to wait for x confirmations. The buyer can take his bitcoin card back.

Sounds good, doesn't it?

I started this topic to hopefully transform this into reality. So what do you think? How to get this into a cheap yet effective system?

Raphy

[1715285622]

1715285622

[Stephen Gornick]

To bring bitcoins to the physical world, we need a system that is largely available and cheap (exit the smartphones)

Smartphones are largely available and relatively cheap.  As these are produced in massive quantities, unit prices are coming down.  In parts of the developing world, sub-$100 androids are sold, for instance. 

When you wanna buy something, you insert the card into the vendor reader. This reader is connected to a computer on wich a special software is running. The software, when a wallet.dat in a memory card pops in, run a bitcoind instance with this wallet, to send the agreed amount.
For security, the user has to enter is passphrase (much like he would enter a PIN with a credit card).

You are missing the next step.  The vendor's card reader was hacked by Bob.  Minutes after the customer leaves the store, all of the keys from the wallet.dat were used to spend the reaming balance of the wallet.

So that specific approach won't work.

There have been a number of approaches.  Here's some discussion on the topic:
 - http://bitcointalk.org/index.php?topic=7539.0