Bitcoin Wallet 2.41 released!

[Andreas Schildbach]

I'm proud to announce version 2.41 of Bitcoin Wallet.

The changes are mostly under the hood, but some of them are massive:

• Seriously reduced bandwidth and CPU usage due to usage of bloom filters on peer connections
• Faster connection setup to peers
• Ability to spend your own change instantly, without waiting for confirmation
• No need to manually disconnect any more for any of the preferences
• Preference for showing the connectivity indicator
• Shortcut to request coins by long tapping on QR code
• Enhanced Peer monitor to show more info about peers, e.g. hostname
• Fallback for fetching exchange rates (bitcoincharts first, then blockchain)
• Lots of small improvements and bugfixes
• Based on bitcoinj 0.7

The bloom filter feature depends on seeing at least one bitcoin-qt/bitcoind 0.8.0 (protocol version 70000+) to download blocks from. As of today, the chance for this is roughly 50% and will increase as the new version spreads. If you want to help, update your bitcoin-qt now.

Download/update from Google Play:
https://play.google.com/store/apps/details?id=de.schildbach.wallet

Direct download:
https://code.google.com/p/bitcoin-wallet/downloads/list

Source:
https://code.google.com/p/bitcoin-wallet/source/checkout


Thanks to everyone who contributed to Bitcoin Wallet and bitcoinj. Mike Hearn and Matt Corallo earn extra hugs for making bloom filters a reality!

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[wyodude]

Updated, does seem to be noticeably faster. Thank you for your work.

[coqui33]

Is there any way to import a pre-existing private key?

[wyodude]

Is there any way to import a pre-existing private key?

+1

[Jouke]

Yes there is, but it is not real easy.

Make a backup, decrypt that file, put your private key in, encrypt that file again, import it as a backup.

 https://bitcointalk.org/index.php?topic=4384.msg1287794#msg1287794

[datafish]

When I first ran v. 2.41, it gave me a warning about older versions of Android not being supported in the future and said that I should transfer my bitcoins out of the wallet.  However, when I try to send now, it crashes.  Is there any way to roll back to the previous version or import the private keys into another client?  Thanks.

[datafish]

Ok,  I was able to download the apk for version 2.39 from google code, install it and transfer my coins out.

[coqui33]

Yes there is, but it is not real easy.

Make a backup, decrypt that file, put your private key in, encrypt that file again, import it as a backup.

 https://bitcointalk.org/index.php?topic=4384.msg1287794#msg1287794

Thank you. That was helpful. I saved the (encrypted) privkey from the Android wallet to a file, then moved the file to a windows machine, then downloaded OpenSSL for Windows (lite), then learned enough about OpenSSl to decrypt the file, then decrypted the file, then copied the exported decrypted privkey and pasted it into Blockchain.info in order to test it. Blockchain.info said that it was a "compressed" privkey and that i should sweep it, rather than load it (something about Android). At that point, I realized that I would have to learn how to use OpenSSL to re-compress and re-encrypt my pre-existing privkey before I could move the file back to Android in order to import it back into the Android wallet.

I decided that this process was too steep a learning curve for a one-time operation. So, for my cell-phone spending money, for now I am sticking with BitCoinSpinner.

This is a shame. I do not fully trust BitcoinSpinner because it does not use standard blockchain nodes, whereas I can set Bitcoin Wallet 2.41 to use my own personal trusted bitcoind 0.8 node (at pc.backintyme.com), as well as other nearby nodes. I shall check back now and then to see if perhaps the next release of Android wallet makes privkey management more straightforward.

Thanks again.

[Mike Hearn]

Why don't you just .... send the money from your desktop to your wallet?

Importing private keys is deliberately awkward because there are so many ways people can make mistakes and end up accidentally creating double spends. Perhaps in future having multiple devices all sharing the same wallet will be easier and safer but for now, you can just send the money.

[coqui33]

Why don't you just .... send the money from your desktop to your wallet?

Why don't I send the money from my desktop to my wallet? There is no easy way to answer that.

First, I do not keep any money in any desktop. I keep my savings in several privkeys, none of which is implemented in software anywhere. When I must spend money from savings, I temporarily import one of the privkeys into software (armory, blockchain.info, or the like), spend the money, and immediately delete the privkey from the software. I may have inadvertently misled when said that I run a bitcoin-d node on a server. But I do not keep any active privkeys there. I run it just to help the cause, since I must run the server 24/7 for other reasons.

Second, the little money that I must keep on hand (less than one btc), I keep in a privkey that is loaded into BitcoinSpinner both on my smartphone and also on my tablet (same privkey). That way, I can spend from the same privkey, no matter which Android device I happen to be holding.

I keep track of the balances in my several savings privkeys as well as in the petit-cash privkey with the "WalletBalance" Android app.

The reason that your question is hard to answer is that I do not see bitcoins the way many people do. Many people visualize their bitcoins as residing in this wallet or that, in one computer or another. And so the question "Why not move the money from this wallet to that wallet?" makes sense to them. To me, my bitcoins are in my privkeys, which are dispersed across all the nodes. Wallet software is merely a temporary tool for spending money out of a privkey. Again, with the exception of the petit cash that I carry in my phone and tablet, none of my bitcoins are in wallets anywhere. All are in privkeys in the cloud.

[Mike Hearn]

Yeah, for unusual use cases like yours right now the Bitcoin Wallet app might not be appropriate. It can support what you're doing, but it'll import private keys more slowly than an app like Spinner will. The flip side of course is that with apps like blockchain.info or spinner the server knows all your transaction history.

I think in future having the same keys shared by different apps will become more common. It's safe as long as none of the apps get out of sync with each other. The problem is if they do get out of sync, it's tough to recover right now. We probably need more code to check the timestamps on block headers vs some source of real time to avoid problems caused by the users clocks being set wrong, and forbid spending until the chain head is not too far away from real time.

[coqui33]

The flip side of course is that with apps like blockchain.info or spinner the server knows all your transaction history.

Correct. I wake up at 3 A.M. fretting over this... seriously... I am paranoid about anyone knowing what I have and where I keep it. Spinner and blockchain.info are merely temporary solutions until something more private comes along.

I think in future having the same keys shared by different apps will become more common. It's safe as long as none of the apps get out of sync with each other. The problem is if they do get out of sync, it's tough to recover right now.

I agree. As you say though, this should be soluble with some serious thought towards limiting clashes caused by time and recipient-address overlap. I guess we just have to be patient.

[Jouke]

Yes there is, but it is not real easy.

Make a backup, decrypt that file, put your private key in, encrypt that file again, import it as a backup.

 https://bitcointalk.org/index.php?topic=4384.msg1287794#msg1287794

Thank you. That was helpful. I saved the (encrypted) privkey from the Android wallet to a file, then moved the file to a windows machine, then downloaded OpenSSL for Windows (lite), then learned enough about OpenSSl to decrypt the file, then decrypted the file, then copied the exported decrypted privkey and pasted it into Blockchain.info in order to test it. Blockchain.info said that it was a "compressed" privkey and that i should sweep it, rather than load it (something about Android). At that point, I realized that I would have to learn how to use OpenSSL to re-compress and re-encrypt my pre-existing privkey before I could move the file back to Android in order to import it back into the Android wallet.

I decided that this process was too steep a learning curve for a one-time operation. So, for my cell-phone spending money, for now I am sticking with BitCoinSpinner.

This is a shame. I do not fully trust BitcoinSpinner because it does not use standard blockchain nodes, whereas I can set Bitcoin Wallet 2.41 to use my own personal trusted bitcoind 0.8 node (at pc.backintyme.com), as well as other nearby nodes. I shall check back now and then to see if perhaps the next release of Android wallet makes privkey management more straightforward.

Thanks again.

You were almost there! Encrypting the file is one option different as decrypting in openssl!

Information about your keys in different formats can be obtained at bitaddress.org

[btcusr]

Watch-only addresses please..

[Andreas Schildbach]

When I first ran v. 2.41, it gave me a warning about older versions of Android not being supported in the future and said that I should transfer my bitcoins out of the wallet.  However, when I try to send now, it crashes.  Is there any way to roll back to the previous version or import the private keys into another client?  Thanks.

I'm sorry about this, it will be fixed in version 2.42 which will be most likely released tomorrow.

It was caused by some Java6 code creeping in, and your phone can only do Java5 unfortunately.

Don't worry, your phone will be supported long enough to move your coins out. And actually if you're happy with the current feature set, you will likely be able to use the app much longer.

[HostFat]

Will you ever add a sync-on-wifi-only option?

[Andreas Schildbach]

I keep my savings in several privkeys, none of which is implemented in software anywhere.

I wonder how you manage to transfer your private keys between devices without accidently leaking them.

If you send them by mail or instant message unencrypted, they are obviously leaked.
If you copy them to the clipboard (cut & paste), any application can steal them. I am sure there is already malware that monitors the clipboard.
If you copy them to external storage on Android unencrypted, again any app can steal them.
If you view and scan them using QR-codes, observers can snapshot them as well.

This is why I am extremely cautious regarding import and export of private keys and always require encryption. Note that MultiBit uses the same scheme, so you should be able to exchange keys without the openssl step inbetween. We have deliberately chosen this openssl standard, because it should be easy to implement by other applications as well.

Some months ago I have - in a private branch - implemented the ability to display private keys as QR and import them by scanning. I will not merge this as is, but if you want you can compile it yourself (and enhance perhaps, to make it more secure).

I'm thinking about the possibility to import private keys by sweeping. This would allow for redeeming vouchers / paper wallets, but its probably not what you want.

However, its all just a workaround. The most convenient and secure way to transfer money is signing a Bitcoin transaction.

[Andreas Schildbach]

Will you ever add a sync-on-wifi-only option?

The plan is to make the network so efficient that you don't care. As soon as bloom filtering is supported by virtually all nodes, it should be possible to stay within 2 MB per month with moderate use. Currently only one quarter of peers support bloom filtering, so make sure to update your bitcoin-qt or bitcoind to 0.8.0.

[Syke]

When I first ran v. 2.41, it gave me a warning about older versions of Android not being supported in the future and said that I should transfer my bitcoins out of the wallet.  However, when I try to send now, it crashes.  Is there any way to roll back to the previous version or import the private keys into another client?  Thanks.

I'm sorry about this, it will be fixed in version 2.42 which will be most likely released tomorrow.

It was caused by some Java6 code creeping in, and your phone can only do Java5 unfortunately.

My app crashes when trying to import a private key. Is this the same issue?

[Andreas Schildbach]

My app crashes when trying to import a private key. Is this the same issue?

Depends on the crash. Have you sent a crash report? Which email address did you use (so that I can identify your report)?