Quote from: RealBitcoin on June 14, 2015, 08:44:34 PM

Quote from: dogecoinshop on June 14, 2015, 08:16:24 PM

Quote from: RealBitcoin on June 14, 2015, 08:06:03 PM

A payment takes 10 min to process. In what store can you buy something under 10 minute really?

Sometimes you have to wait 15 min at the tilt because the employee is a moron, if you could do that in 10 min i`d be very happy.

You just buy the stuff quick, pay for it, then put the bought stuff in a safe storage inside the magazine, and go looking at the other products until you wait for verification. Then after the verification is done, pickup your bought goods and leave.

It would change shopping habits, but whatever.

No ,that would make people leave..Really once blockchain see's the transaction you are good .i have stood their and tried to double spend and never succeeded(Testing) So , if you really want bitcoin to be used by the masses . Maybe try going to a real store and spending some ?

Quote from: twister on June 14, 2015, 08:19:20 PM

Quote from: RealBitcoin on June 14, 2015, 08:06:03 PM

A payment takes 10 min to process. In what store can you buy something under 10 minute really?

Sometimes you have to wait 15 min at the tilt because the employee is a moron, if you could do that in 10 min i`d be very happy.

You just buy the stuff quick, pay for it, then put the bought stuff in a safe storage inside the magazine, and go looking at the other products until you wait for verification. Then after the verification is done, pickup your bought goods and leave.

It would change shopping habits, but whatever.

Not all blocks take 10 minutes, that's the average time but some of them I have seen to take more than an hour. It is a minor problem and it has been discussed before but if any store does starts to accept BTC as a payment method then the person paying with bitcoin has to wait until the Tx has received 1 confirmation because the shop owner won't accept payment until it has 1 confirmation and for now this is how it is.

Ok plan B

Have an offchain bitcoin based payment processor designed solely for shop purchases.

You sign up to this payment processor, deposit like 2 bitcoins, and then go on shopping. When you pay for the goods & services you pay directly from the PP's account you hold with them, which would take 15 sec perhaps like if you would buy with credit/debit cards

This would be an easy off-chain solution, and would need a bit of technical integration from the vendor's part.

But i`m sure something like XAPO or similar could come up with an offchain system like this.

plan c

The shop itself should have an internal account with you. Most shops already give out fidelity cards, perhaps they can give out debit cards now and you can have an accoutn with them.

Especially big hypermarkets and plaza's so you just make an account there deposit 2-3 bitcoins when you enter, buy it off and then you leave you can take out the change.

Really? You are so off .
You would need some scripting knowledge as any of the default bitcoin core/qt or other wallets won't allow you to easily execute a double spend.

Any particular reason you want to try this? Just to see how resilient the protocol is? Short of having a ton of mining resources at your disposal, it's going to a bit hard to pull off even a 0 confirmation double spend since most miners will reject the transaction by comparing what's in mempool. For a 1-3 confirmation doubles spend, the difficulty becomes exponentially higher.

In short, there's no GUI 'test a double spend' client that I'm aware of.