Bitcoin Wallet for Android

[Andreas Schildbach]

Sorry, but I have a specific desire to copy my PC wallet to my phone and use it.

You'll probably never be able to copy wallet.dat directly. The closest you can get is exporting and importing the private keys and rescan the blockchain. This is currently not supported in Bitcoin Wallet but maybe will in future (patches welcome).

If you switch your PC wallet to MultiBit, that wallet format (protobuf) is compatible to Bitcoin Wallet. You'll need root on your Android device to push the wallet though.

Whichever route you take, be careful. Its easy to unintentionally double-spend with the same keys in two wallets.

[Bananington]

Sorry, but I have a specific desire to copy my PC wallet to my phone and use it.

You'll probably never be able to copy wallet.dat directly. The closest you can get is exporting and importing the private keys and rescan the blockchain. This is currently not supported in Bitcoin Wallet but maybe will in future (patches welcome).

If you switch your PC wallet to MultiBit, that wallet format (protobuf) is compatible to Bitcoin Wallet. You'll need root on your Android device to push the wallet though.

Whichever route you take, be careful. Its easy to unintentionally double-spend with the same keys in two wallets.

Hey thanks for that solution. I might take that route if I can't succeed in the current route I'm trying.

Sorry for getting off-topic.

[Mike Hearn]

It also means that if your phone is stolen, so are all the funds from your PC.

Though it can be annoying, I think having a separate mobile wallet and then refilling it from time to time is conceptually the simplest/robust/most secure approach.

[imsaguy]

The 'new' version from a few days ago killed my ability to send coins.

[mohawk38]

The 'new' version from a few days ago killed my ability to send coins.

Same here... 

'Sent' transactions are 'greyed', not broadcasted and stay for days. No idea what to do with it..

HTC Desire

[Andreas Schildbach]

The 'new' version from a few days ago killed my ability to send coins.

Followed up on this in the issue tracker:

http://code.google.com/p/bitcoin-wallet/issues/detail?id=100

[imsaguy]

The 'new' version from a few days ago killed my ability to send coins.

Followed up on this in the issue tracker:

http://code.google.com/p/bitcoin-wallet/issues/detail?id=100

Replied.  Basically, it doesn't ever seem like there's a problem to the user.. other than that the coins never show up in the receiving wallet.  There are connections, the send process looks to complete just like all the other times, just nothing actually happens.

[imsaguy]

The 'new' version from a few days ago killed my ability to send coins.

Followed up on this in the issue tracker:

http://code.google.com/p/bitcoin-wallet/issues/detail?id=100

Replied.  Basically, it doesn't ever seem like there's a problem to the user.. other than that the coins never show up in the receiving wallet.  There are connections, the send process looks to complete just like all the other times, just nothing actually happens.

Not a bug with the app, just the stupid transaction fees.  Basically, I was attempting to send something like 51 btc from 4 inputs to a single output and it was being rejected because I didn't include a fee.  Instead, if I sent each of the input amounts separately, they were relayed successfully.

The fees are having the exact opposite of their intended results... a bunch of single, smaller transactions work vs 1 larger transaction that doesn't work.

[vuce]

The 'new' version from a few days ago killed my ability to send coins.

Followed up on this in the issue tracker:

http://code.google.com/p/bitcoin-wallet/issues/detail?id=100

Replied.  Basically, it doesn't ever seem like there's a problem to the user.. other than that the coins never show up in the receiving wallet.  There are connections, the send process looks to complete just like all the other times, just nothing actually happens.

Not a bug with the app, just the stupid transaction fees.  Basically, I was attempting to send something like 51 btc from 4 inputs to a single output and it was being rejected because I didn't include a fee.  Instead, if I sent each of the input amounts separately, they were relayed successfully.

The fees are having the exact opposite of their intended results... a bunch of single, smaller transactions work vs 1 larger transaction that doesn't work.

That means the transaction was larger than 10 kB in size? With only 4 inputs I find this a little bit hard to believe... Either that or the following isn't correct (or there is a bug in the software):

A transaction can be sent without fees if both of these conditions are met:
- It is smaller than 10 (SI) kilobytes (10.000 bytes).
- All outputs are 0.01 BTC or larger.

[mohawk38]

I have just upgraded to v.2.19, but my 2 'frozen' transactions don't seem to move. Could you guys please give me some instructions how to either cancel them or get them through?
 
10/07/2012    1.10598623 BTC (no fee)
12/07/2012    10.00 BTC (0.0005 fee, so it appears as -10.0005)
 
Thanks in advance

[imsaguy]

I have just upgraded to v.2.19, but my 2 'frozen' transactions don't seem to move. Could you guys please give me some instructions how to either cancel them or get them through?
 
10/07/2012    1.10598623 BTC (no fee)
12/07/2012    10.00 BTC (0.0005 fee, so it appears as -10.0005)
 
Thanks in advance

Do you have a backup?  If so, revert to that.  If not, you need to reset your blockchain by going to reset in the preferences and then chosing the disconnect.  When the app reopens, it'll redownload the last 52 weeks of blockchain. [Happy Anniversary Goonie]

Once you're back to a state with no pending transactions, send yourself the whole balance to a different client (like your desktop/laptop).  The fee you tried to pay isn't actually 'paid' until its mined, so you won't lose that .0005.  Once you send that tx, it should successfully get relayed.  From there, you can use your other client to send the two transactions to their original targets.  It seems that by sending the whole balance to a single address, you're increasing the priority and reducing transaction size enough that it relays with no fee.

[mohawk38]

I have just upgraded to v.2.19, but my 2 'frozen' transactions don't seem to move. Could you guys please give me some instructions how to either cancel them or get them through?
 
10/07/2012    1.10598623 BTC (no fee)
12/07/2012    10.00 BTC (0.0005 fee, so it appears as -10.0005)
 
Thanks in advance

Do you have a backup?  If so, revert to that.  If not, you need to reset your blockchain by going to reset in the preferences and then chosing the disconnect.  When the app reopens, it'll redownload the last 52 weeks of blockchain. [Happy Anniversary Goonie]

Once you're back to a state with no pending transactions, send yourself the whole balance to a different client (like your desktop/laptop).  The fee you tried to pay isn't actually 'paid' until its mined, so you won't lose that .0005.  Once you send that tx, it should successfully get relayed.  From there, you can use your other client to send the two transactions to their original targets.  It seems that by sending the whole balance to a single address, you're increasing the priority and reducing transaction size enough that it relays with no fee.

Thanks a lot!
Block chain is being re-downloaded now, lets see whether sending the whole amount solves the problem.

[imsaguy]

Thanks a lot!
Block chain is being re-downloaded now, lets see whether sending the whole amount solves the problem.

If you have many transactions using the app, while you're catching up, you'll want to close the app periodically using the disconnect option.  If not, it might crash out with an out of memory error.  When I say many, I'm talking over a 100 or 200.  I know many people don't use it very often, but I tend to use it for a lot of day to day stuff, so have a decent amount of transactions on it. 

[mohawk38]

Another day, same shit...
 
Andreas, if you read this, please help me to get my money out of my Bitcoin Wallet... I will provide you with any info you need, just let me know.
 
HTC Desire, Android 2.2.2, Bitcoin Wallet v.2.20
 
I have re-downloaded blockchain, all my 'frozen' transactions disappeared just confirming they were not broadcasted, so I got the initial position of my Bitcoin Wallet. I made some attempts to send some bitcoins out, with or without fees - it does not work. All the transactions appeared as 'pending', stayed in this status indefinitely, and blockchain.info knows nothing about them.
 
I have re-downloaded blockchain once again, and made one more attempt to send out 0.90 BTC with a fee of 0.0005 to 1P31PQZAemC1pejJSiMULSzdzqBB4Hkjhr, that should be pretty normal, nothing criminal, right? This time I've saved a log of the process:

----------------------------------------------------
W/System.err(  817): 26819028 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.MemoryPool - [50.82.218.0]:8333: Announced new transaction [1] 81afda18aa0d78f27e952dcb6dce916fd0b95468982f7bf54cffc4a1b62bbe09
W/System.err(  817): 26819526 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.Peer - Received broadcast tx 81afda18aa0d78f27e952dcb6dce916fd0b95468982f7bf54cffc4a1b62bbe09
W/System.err(  817): 26819527 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.MemoryPool - [50.82.218.0]:8333: Adding tx [1] 81afda18aa0d78f27e952dcb6dce916fd0b95468982f7bf54cffc4a1b62bbe09 to the memory pool
I/System.out(  817): about to send 90000000 (BTC 0.90) to 1P31PQZAemC1pejJSiMULSzdzqBB4Hkjhr
W/System.err(  817): 26820747 [main] INFO com.google.bitcoin.core.Wallet - Creating send tx to 1P31PQZAemC1pejJSiMULSzdzqBB4Hkjhr for 0.90
W/System.err(  817): 26820748 [main] INFO com.google.bitcoin.core.Wallet - Completing send tx with 1 outputs totalling 0.90
W/System.err(  817): 26820749 [main] INFO com.google.bitcoin.core.Wallet -   with 9.77 coins change
W/System.err(  817): 26820809 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.MemoryPool - [50.82.218.0]:8333: Announced new transaction [1] ce55dd20981b187418daf6fb5c5fed55b4ba75a6855a23ad372319da37899e91
W/System.err(  817): 26820948 [main] INFO com.google.bitcoin.core.Wallet -   completed dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820949 [main] INFO com.google.bitcoin.core.Wallet - commitTx of dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820950 [main] INFO com.google.bitcoin.core.Wallet -   4962f73fddeac67658dac94ef3d3724778466ddabaef55c618b9468dce3ea6a7 prevtx <-unspent
W/System.err(  817): 26820951 [main] INFO com.google.bitcoin.core.Wallet -   4962f73fddeac67658dac94ef3d3724778466ddabaef55c618b9468dce3ea6a7 prevtx ->spent
W/System.err(  817): 26820951 [main] INFO com.google.bitcoin.core.Wallet - ->pending: dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820969 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [91.121.120.119]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820971 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [188.96.117.114]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820998 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [50.82.218.0]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26820999 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [87.139.154.234]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
I/System.out(  817): wallet saved to: '/data/data/de.schildbach.wallet/files/wallet-protobuf', took 46ms
W/System.err(  817): 26821038 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [62.75.216.13]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26821040 [Peer group thread] INFO com.google.bitcoin.core.PeerGroup - [78.46.36.3]:8333: Sending transaction dc37ffde1ac5b4918fcd1498ea4f818e667b5f862a9056d6e63c6ae3a5c75d31
W/System.err(  817): 26821178 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(bitseed.xf2.org/91.121.120.119:8333): Socket is disconnected
W/System.err(  817): 26821179 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.PeerGroup - Connecting to Peer(dnsseed.bitcoin.dashjr.org/108.60.150.133:8333)
W/System.err(  817): 26821239 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.Peer - Received broadcast tx ce55dd20981b187418daf6fb5c5fed55b4ba75a6855a23ad372319da37899e91
W/System.err(  817): 26821240 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.MemoryPool - [50.82.218.0]:8333: Adding tx [1] ce55dd20981b187418daf6fb5c5fed55b4ba75a6855a23ad372319da37899e91 to the memory pool
W/System.err(  817): 26821243 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(dnsseed.bitcoin.dashjr.org/78.46.36.3:8333): Socket is disconnected
I/dalvikvm(  817): Jit: resizing JitTable from 16384 to 32768
I/System.out(  817): wallet saved to: '/data/data/de.schildbach.wallet/files/wallet-protobuf', took 72ms
W/System.err(  817): 26821347 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(bitseed.xf2.org/62.75.216.13:8333): Socket is disconnected
W/System.err(  817): 26821347 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Download peer died. Picking a new one.
W/System.err(  817): 26821348 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Unsetting download peer: Peer(bitseed.xf2.org/62.75.216.13:8333)
D/dalvikvm(  817): GC_FOR_MALLOC freed 18372 objects / 879536 bytes in 83ms
W/System.err(  817): 26821339 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.TCPNetworkConnection - Announcing ourselves as: /BitCoinJ:0.5.2/Bitcoin Wallet:2.20/
W/System.err(  817): 26821445 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Setting download peer: Peer(dnsseed.bitcoin.dashjr.org/188.96.117.114:8333)
W/System.err(  817): 26821445 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Unsetting download peer: Peer(dnsseed.bitcoin.dashjr.org/188.96.117.114:8333)
W/System.err(  817): 26821445 [PeerGroup-2-thread-1] INFO com.google.bitcoin.core.PeerGroup - Setting download peer: Peer(dnsseed.bitcoin.dashjr.org/188.96.117.114:8333)
I/System.out(  817): wallet saved to: '/data/data/de.schildbach.wallet/files/wallet-protobuf', took 33ms
I/System.out(  817): Peer connected, 5 peers connected
I/System.out(  817): Peer connected, 4 peers connected
I/System.out(  817): Peer connected, 3 peers connected
D/SurfaceFlinger(   92): Layer::setBuffers(this=0x6c82f8), pid=817, w=1, h=1
D/SurfaceFlinger(   92): Layer::setBuffers(this=0x6c82f8), pid=817, w=1, h=1
D/SurfaceFlinger(   92): Layer::requestBuffer(this=0x6c82f8), index=0, pid=817, w=278, h=146 success
W/System.err(  817): 26821583 [PeerGroup-2-thread-5] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(bitseed.xf2.org/87.139.154.234:8333): Socket is disconnected
W/System.err(  817): 26821592 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(dnsseed.bitcoin.dashjr.org/50.82.218.0:8333): Socket is disconnected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
I/System.out(  817): Peer connected, 2 peers connected
I/System.out(  817): Peer connected, 1 peers connected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
W/System.err(  817): 26821851 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.TCPNetworkConnection - Connected to peer: version=60001, subVer='/Satoshi:0.6.99/', services=0x1, time=Wed Jul 18 14:30:41 GMT+03:00 2012, blocks=189645
W/System.err(  817): 26821852 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.PeerGroup - Peer(dnsseed.bitcoin.dashjr.org/108.60.150.133:8333): New peer
W/System.err(  817): 26821852 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.PeerGroup - [108.60.150.133]:8333: Announcing 1 pending wallet transactions
I/System.out(  817): Peer connected, 2 peers connected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
W/System.err(  817): 26822045 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.PeerGroup - Connecting to Peer(bitseed.xf2.org/69.64.34.118:8333)
W/System.err(  817): 26822198 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.TCPNetworkConnection - Announcing ourselves as: /BitCoinJ:0.5.2/Bitcoin Wallet:2.20/
W/System.err(  817): 26822545 [PeerGroup-2-thread-2] WARN com.google.bitcoin.core.Peer - Received alert with invalid signature from peer Peer(dnsseed.bitcoin.dashjr.org/108.60.150.133:8333): URGENT: upgrade required, see http://bitcoin.org/dos for details
W/System.err(  817): 26822547 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.MemoryPool - [108.60.150.133]:8333: Announced new transaction [1] ce55dd20981b187418daf6fb5c5fed55b4ba75a6855a23ad372319da37899e91
W/System.err(  817): 26822548 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.Peer - Received getdata message: com.google.bitcoin.core.GetDataMessage@46530cd8
W/System.err(  817): 26822549 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.Peer - Sending 1 items gathered from listeners to peer
W/System.err(  817): 26822593 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.TCPNetworkConnection - Connected to peer: version=60001, subVer='/Satoshi:0.6.99/', services=0x1, time=Wed Jul 18 14:30:41 GMT+03:00 2012, blocks=189645
W/System.err(  817): 26822594 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.PeerGroup - Peer(bitseed.xf2.org/69.64.34.118:8333): New peer
W/System.err(  817): 26822594 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.PeerGroup - [69.64.34.118]:8333: Announcing 1 pending wallet transactions
I/System.out(  817): Peer connected, 3 peers connected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
D/dalvikvm(  817): JIT code cache reset in 8 ms (1048552 bytes 1/0)
D/dalvikvm(  817): GC_FOR_MALLOC freed 25990 objects / 998312 bytes in 94ms
W/System.err(  817): 26823047 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.PeerGroup - Connecting to Peer(bitseed.xf2.org/177.71.186.54:8333)
W/System.err(  817): 26823319 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.TCPNetworkConnection - Announcing ourselves as: /BitCoinJ:0.5.2/Bitcoin Wallet:2.20/
W/System.err(  817): 26823375 [PeerGroup-2-thread-4] WARN com.google.bitcoin.core.Peer - Received alert with invalid signature from peer Peer(bitseed.xf2.org/69.64.34.118:8333): URGENT: upgrade required, see http://bitcoin.org/dos for details
W/System.err(  817): 26823385 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.Peer - Received getdata message: com.google.bitcoin.core.GetDataMessage@4662cbb0
W/System.err(  817): 26823386 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.Peer - Sending 1 items gathered from listeners to peer
W/System.err(  817): 26823602 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(bitseed.xf2.org/177.71.186.54:8333): Connection reset by peer
W/System.err(  817): 26823778 [PeerGroup-2-thread-4] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(bitseed.xf2.org/69.64.34.118:8333): Socket is disconnected
I/System.out(  817): Peer connected, 2 peers connected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE
W/System.err(  817): 26824051 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.PeerGroup - Connecting to Peer(dnsseed.bitcoin.dashjr.org/70.66.25.248:8333)
W/System.err(  817): 26824324 [PeerGroup-2-thread-6] INFO com.google.bitcoin.core.TCPNetworkConnection - Announcing ourselves as: /BitCoinJ:0.5.2/Bitcoin Wallet:2.20/
W/System.err(  817): 26824578 [PeerGroup-2-thread-2] INFO com.google.bitcoin.core.PeerGroup - Error talking to Peer(dnsseed.bitcoin.dashjr.org/108.60.150.133:8333): Socket is disconnected
I/System.out(  817): Peer connected, 1 peers connected
I/LSState (   92): EventReceiver:android.intent.action.NOTIFICATION_UPDATE

[Mike Hearn]

Hmm, that's odd. For some reason the peer nodes must be rejecting the transaction, because it's very clearly sending and announcing the transactions multiple times.

What we really need to see now is a log from the other side.

mohawk38, do you have a synced Bitcoin-Qt client? If not, you can find me online at some point (I am TD in #bitcoin-dev and will be around for a few hours now, maybe again tomorrow during the day time Central European time) - then you can connect to my node.

I suspect this line is the smoking gun:

W/System.err(  817): 26823375 [PeerGroup-2-thread-4] WARN com.google.bitcoin.core.Peer - Received alert with invalid signature from peer Peer(bitseed.xf2.org/69.64.34.118:8333): URGENT: upgrade required, see http://bitcoin.org/dos for details

The alert does not have an invalid signature, so it indicates a problem I've seen hints of before - some old Android devices appear to have a broken BigInteger implementation that renders ECDSA calculations silently incorrect (!!!!)

If you have such a broken device, you may be simply unable to use any non-server side wallet with it. Even clients like BitcoinSpinner would be unable to operate correctly.

We still need to prove that this is the case. If there's a way to get a copy of the wallet I can check the signature myself, or you could connect to a node I run and I'd check debug.log for a signature verification error when you're around.

[mohawk38]

Thanks for reply Mike,
 
Yes I have synced Qt client on WinXP computer.
 
Could you please instruct me which steps should I perform to transfer my wallet from my 'HTC Desire' to 'Galaxy Tab 10.1' ? Both devices have 'Bitcoin Wallet' installed. Is it possible at all?

Thanks in advance.

[Mike Hearn]

OK, first we need to figure out the problem.

Go into preferences (advanced) in your Bitcoin Wallet on the HTC Desire and set "trusted peer" to be the IP address of your computer with Bitcoin-Qt. Then use "disconnect" and restart the app. Now find the debug.log file on your desktop computer generated by Bitcoin-Qt and upload it somewhere we can see it. Look for errors talking about bad signatures.

Andreas will have to help you get the wallet off the device. I don't know how to do that. It should be possible though.

[Andreas Schildbach]

If your phone is rooted, you can copy your wallet from /data/data/de.schildbach.wallet/files/wallet-protobuf

If you can't root your phone, I would need to send you a special version that has the ability to copy your wallet to your sdcard. However, this is a quite dangerous feature, as all other apps you got on your phone can steal your wallet/private keys from the sdcard easily.

[OneEyed]

If your phone is rooted, you can copy your wallet from /data/data/de.schildbach.wallet/files/wallet-protobuf

If you can't root your phone, I would need to send you a special version that has the ability to copy your wallet to your sdcard. However, this is a quite dangerous feature, as all other apps you got on your phone can steal your wallet/private keys from the sdcard easily.

In any case, it would be a good idea to be able to encrypt the private keys: if your phone is rooted (and I would think that the intersection between people rooting their phones and people using bitcoins is not empty), another application is more likely to be able to access the wallet-protobuf content. And you could only allow backuping a wallet on the sdcard if the private keys are protected by a passphrase.

[Andreas Schildbach]

In any case, it would be a good idea to be able to encrypt the private keys.

Encrypting private keys in the wallet is already underway in BitCoinJ. It will probably take a cycle for it getting into the apps.

if your phone is rooted (and I would think that the intersection between people rooting their phones and people using bitcoins is not empty), another application is more likely to be able to access the wallet-protobuf content.

Why is that? To my understanding, apps would still need to expoit security bugs, and the mere existence of them is unrelated to wether you have rooted your phone or not.