
Bitcoin Android Released - barmstrong
https://github.com/barmstrong/bitcoin-android
======
tapvt
While I can't speak to the legal or political implications of the product or
supporting infrastructure, I'm thrilled with the idea of a mobile application
that provides for the exchange of "currency" in an autonomous manner.

The exchange of value outside of the established models (Gov't issued currency
/ PayPal / Google Checkout / next iteration thereof) has the potential to
provide a huge opportunity for those of us involved in the space of online
media and web applications.

Mobile implementations to bring the utility of the Bitcoin project into the
palm of the hand bridge an intimidating virtual-to-real gap for many potential
users.

In my opinion, the development of this mobile application, as well as similar
projects, is a first step towards the more widespread adoption of the Bitcoin
currency, in whatever (hopefully at least semi-legal, and legitimate) form it
may finally take.

I'll observe with great interest.

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jerguismi
I like the server-client model more, for example BitPay which uses
instawallet.org (<http://forum.bitcoin.org/index.php?topic=24452.0>).

There is also mtgox vouchers-app:
<http://forum.bitcoin.org/index.php?topic=25307.0>

These apps use QR codes, but I think the way to go is NFC communication.

The benefit is instant transactions with server-client model, but on the
downside you have to rely on 3rd party. I think it isn't that big downside,
since you have always handed your money to 3rd party before bitcoin...

~~~
barmstrong
The entire production blockchain is 14MB right now. We keep this on the SD
card of the phone. Many smartphones today have 8GB SD cards or more, so 14MB
is not a big deal.

I agree though, I think a thin-client or server-client model would be better
long run. There just isn't a service I'd trust with it currently.

~~~
wcoenen
Where are you getting the 14MB figure? I see a blk00001.dat file on my PC
which is already more than 300MB.

The latest compressed blockchain download available here at the time of
writing is 280MB: [http://bitcoin.bluematt.me/bitcoin-nightly/blockchain-
nightl...](http://bitcoin.bluematt.me/bitcoin-nightly/blockchain-nightly/)

It is known that even PCs won't be able to handle the full blockchain
eventually, let alone smartphones. Supernodes will be needed if bitcoin
becomes popular. <https://en.bitcoin.it/wiki/Scalability>

__edit __: I see now that there is indeed a 14MB blockchain file in the
source:[https://github.com/barmstrong/bitcoin-
android/blob/master/as...](https://github.com/barmstrong/bitcoin-
android/blob/master/assets/prodnet.blockchain). I suppose this is not the full
blockchain, but just the block headers. This is described as "Simplified
Payment Verification" in Satoshi's paper.

~~~
barmstrong
It could very well be just block headers, to be honest I'm not sure (didn't
realize the desktop version was that big). We're using the bitcoinj library
and contributing back some patches along the way. Mike Hearn at Google wrote
the blockstorage and deserves a ton of credit for it:
<http://code.google.com/p/bitcoinj/>

~~~
tudorw
"BitCoinJ implements the "simplified payment verification" mode of Satoshis
paper. It does not store a full copy of the block chain, rather, it stores
what it needs in order to verify transactions with the aid of an untrusted
peer node."

one click * HN user base = global time saving :)

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thinkcomp
Am I the only one interested in mobile payment apps that let you buy real
things with dollars? Are dollars suddenly that uncool?

~~~
barmstrong
You're right, it's pretty theoretical at this point. But as Chris Dixon points
out, most big ideas start out looking like toys:
[http://cdixon.org/2010/01/03/the-next-big-thing-will-
start-o...](http://cdixon.org/2010/01/03/the-next-big-thing-will-start-out-
looking-like-a-toy/)

~~~
thinkcomp
Don't be ridiculous. The USD isn't about to be disintermediated. The Euro,
maybe...but then by the USD.

~~~
njs12345
Bitcoin is unlikely to replace the dollar, but if I were Paypal I'd be
worried..

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click170
Oh good, just what I needed. _Less_ battery life on my phone.

~~~
bluedanieru
Word. I imagine it would take my old HTC Magic about 9 years to process the
block chain. Also even though I wouldn't keep much BTC in this wallet, I don't
like the idea of just storing it 'in the cloud' or whatever.

~~~
barmstrong
We actually prepackage a recent blockchain with the app when you download it.
So it only needs to udpate the last bit the first time you run it (< 1 minute
over wifi). After that future updates are near instant (a few seconds) over 3G
or WiFi.

~~~
mcantelon
Brilliant software... have been waiting for this.

One obvious question: is there anything to prevent someone from repackaging
this, as it's open source, and modifying it to rob folks?

~~~
mike-cardwell
No. Just like any other open source software. It's also possible that people
who download the apk from the Android Market Place are getting a backdoored
version of the software.

This relies on trust.

Does anyone remember Paypal updating their iPhone app last year to do SSL
certificate verification because up until that point it was trivially
MITM'able?

------
bahman2000
"Wallet file backed up in the cloud (synced to your Google account) in case
you lose your phone." Here's hoping that the wallet is encrypted.

~~~
brandoniles
We make no guarantees about the security of the backup. This is beta software
:)

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Rassah
Can you tell us where exactly the wallet.dat file and the block chain are
stored on the android? I sent 0.01BTC to my phone a while ago, and it has yet
to show up (so I'd like to grab the wallet.dat for backup), and it's showing a
swirling circle at the top, meaning it's still downloading, and I'd like to
check if it's actually doing anything (file size increasing?)

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joejohnson
Can anyone speak to how this app works? Does the phone store a local copy of
the block chain?

~~~
sgornick
<http://news.ycombinator.com/item?id=2732839>

------
hippich
crashed for me =(

