Bounty 30 BTC - Bump 2 phones together and transfer Bitcoins.

[dogisland]

Update : I've raised the bounty.

I want to merge BumpPay and Instawallet.

BumpPay http://mashable.com/2012/03/29/bump-pay/ uses your phones orientation and location api to to detect the intention to make a payment. They have an API so they can handle all the location stuff for us. http://bu.mp/api

https://www.instawallet.org/w/2X3HgsXKf7BEGYbn10yP1qc4uPMNn0PXNg Instant wallets. cool.

What I want.

I want a simple HTML5 web page that works on android and iphone.

1. User goes to the site and they are immediately redirected to a unique URL, i.e. BitBump/asd2345dfg

2. The user needs to bookmark this page.

3. The page has a unique bitcoin address and a balance. Send coins to the address and the balance will update. You can source address balances from blockchain.info. The address you can generate from the unqiue URL using the Bitcoin Javascript libraries.

4. The page has a make payment button. The user presses the button and enters an amount.

Now The exciting bit.

5. When the user bumps phones with another BitBump user running the web page the funds transfer from one account to another. You can detect phone motion in Javascript http://www.html5rocks.com/en/tutorials/device/orientation/

6. The user receving the funds will get a notification on their phone.

7. Congratulations, you've just made any smartphone a payment device in seconds.


Any questions just ask, I run Strongcoin.com so I'm familiar with the technical side of generating Bitcoin payments via Javascriot.

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[ElectricBrain]

I think this is a solid idea, but you may want to put it in another sub-forum. This is beyond the scope of the "newbies" board.

[bitbonus]

Nice idea, but I do not think you will have anyone making it for only 10BTC

[Stephen Gornick]

Most of the work is already done if you wanted to do this as an Android app as well ...

BitPay mobile app ..., open source, interfaces with InstaWallet

 - https://github.com/warpi/BitPay

[Stephen Gornick]

the funds transfer from one account to another.

That's the "and magic happens here" right?

In one phone you have a private key which has funds.  You bump, and you transfer what ... the private key?   If so, then you aren't transferring a some amount, you are transferring the ability to spend anything received at that address.  So I don't think that's what you meant.

So instead you are describing the one side creating (in Javascript) the spend transaction?

The Javascript in BlockChain.info does this but you still need to send it to a host to broadcast it.  
 - http://www.blockchain.info/pushtx

Or am I missing something?

[Update: After re-reading this, I get it.  You will create an instawallet type site BitBump.com and this transaction would use the API (presumably) to transfer the funds from one account on the hosted wallet to another account.  Got it.
With InstaWallet, that would be done using the /payment API method (with use_green_address=true).
 - https://www.instawallet.org/static/api.html ]

[dogisland]

This is beyond the scope of the "newbies" board.

I thought I'd give the newbies a chance first, and they can't post in other forums.

[Update: After re-reading this, I get it.  You will create an instawallet type site BitBump.com and this transaction would use the API (presumably) to transfer the funds from one account on the hosted wallet to another account.  Got it.
With InstaWallet, that would be done using the /payment API method (with use_green_address=true).
 - https://www.instawallet.org/static/api.html ]

Nearly.

There would be no hosted wallet and no database on the server. All transaction would go over the Bitcoin network.

So let's say I have BitBump.com/gfgfweriwrysjjkf randomly generated for me.

Using "gfgfweriwrysjjkf" as a private key (SHA2) I get 1Hu5MmBMni7VE5p2y8H1boGQzAuoyyxYAL as a public key. All this can be done in Javascript (BitcoinJS).

I can send coins to that address and the page (BitBump.com/gfgfweriwrysjjkf) can update it's balance by accessing blockchain.info API i.e.  https://blockchain.info/q/getreceivedbyaddress/1Hu5MmBMni7VE5p2y8H1boGQzAuoyyxYAL

Now, if a payment is to be sent, the page can create the transaction in Javascript and send it onto the network via Strongcoin (I have a non public API for sending TX's).

So the serverside waits for transfer requests (i.e. a bump) when it does it uses the bump api to see who's phone is nearby waiting to receive. All the server side needs is the destination public address of the nearby phone and the web page can create the TX.