There are at least two actual clients for Android and half a dozen "thin clients" that connect to a bitcoin server at home. As the thin clients are kind of complicated installs, I recommend Bitcoin Wallet by Andreas Schildbach.
There are a few questions of security as both apps have no way (that I'm aware of) to import/export/backup wallets and it's ...
For Mycelium, the actual file that contains the encrypted keys are in the sqlite3 file. You can see in the source code that though there is in-memory storage, it's used mostly for testing and that the main way in which Mycelium data is stored is in a sqlite3 file. Sqlite, if you aren't familiar, is a very simple relational database that contains the whole ...
Don't use Bitcoin by Bitcoin Android. It is unmaintained, it starts crashing and doesn't load anymore, and there is no way to get your bitcoins out. Someone should really get the developer to take it down. I'm emailing him again now.
Use Bitcoin Wallet. It is maintained by the same team that creates the bitcoinj android library. It is the most reliable app.
If you want to keep your private keys secret (on your phone, that is), I'd recommend
Bitcoin Wallet for Android
The app also does not imply any trust in single servers, as it manages the block chain on-device.
Since I don't know what wallet app on Android you're using, I'll give an answer that should work for any:
If you create an account at Coinbase, you can import your private keys and then send them to an address on your Android wallet. This requires the private keys being in plain text. If your private key export is encrypted (with a password you gave it) or ...
The quote in the documentation is a remnant from the http://code.google.com/p/bitcoin-wallet/ which the app was forked from.
At present it does not do any blockchain validation. I would like to have it so instead of downloading the full transactions from blockchain.info the client asks for the block hashes that contain transactions of interest. It can then ...
I would try option 1 first, if you can find the right version of the library. I'd be willing to try making a general purpose tool to do it, but don't have an Android phone. Is there any way you can make a new, empty wallet and put a copy online somewhere along with a corresponding bitcoin address or two?
If you're attempting option 2, you probably know at ...
[Obsolete answer, see below]
As an update: current versions of the Bitcoin app have a "Back up Keys" feature. This writes a backup of all the keys in the wallet to a file named bitcoin-wallet-keys-YYYY-MM-DD (using the current date) in the phone's storage, which you can then copy or transfer wherever you want. The file is encrypted with a password you ...
This is valid, and there are even smaller types as well. Be aware that Bitcoin no longer really uses ASN.1 DER, but a even more restrictive subset of it. ASN.1 itself as it turns out is not deterministic or platform independent in many implementations, which is a source of consensus failure. For reference, here is how to encode signatures correctly in ...
I don't think the Bitcoin Foundation or any similar authority has designated an official or preferred Android app, not in the same way that Bitcoin Core is the "official" desktop client because it is the reference implementation.
But the most popular one seems to be Bitcoin Wallet by Andreas Schildbach.
From this discussion: How to create a checkpoint file
Run mvn exec:java -Dexec.mainClass=com.google.bitcoin.tools.BuildCheckpoints in the tools/ directory from the bitcoinj repository.
BuildCheckpoints expects you to have a fully synced local Bitcoin-Qt/bitcoind instance running.
I consider the Blockchain.info Wallet Android App the best one on the market. It's no true client but an e-wallet but you can manage your own true wallets and addresses and your private keys are stored encrypted. The decryption happens on your phone.
The Bitcoin Wallet project recently included detailed instructions on how to extract your key pairs for exactly this purpose. In the section Recovering from protobuf wallet format, skip to the paragraph beginning with
You can also get a list of the private keys...
(Here is a historic version of that guide*, should it ever disappear)
I have now completed ...
There are two types of wallets:
A full node client uses the peer-to-peer network to validate transactions and blocks and to relay information to other peers. To verify all transactions, the entire blockchain (~145G) acts as a dependency to enable the tracing of transactions on the network.
SPV, Simplified Payment Verification, is ...
I wrote up a detailed answer to this some ago. Essentially, you will need to root your phone and extract the wallet file with apd.
After you've got that you can decode it by looking within the serialized wallet with a Java debugger attached looking for an ECKey reference. Then, once you have the private key you can simply hand it over to MtGox who will do ...
You can also use an e-wallet or an exchange to send bitcoins. Most websites can be accessed with a phone so you don't have to install anything.
MtGox already has a mobile application that you can use to access your account. I am sure other applications and mobile sites will appear soon.
You can use online wallet, like StrongCoin, then it doesn't matter where you access it from.
You need to use an Android client that allows for private key import/export. I'm not sure which Android client does this, but for Windows/Linux you either can look for some tools for altering the wallet.dat for the standard Client, or use an alternative client with ...
If you really want to create a custom bitcoin application, forking from an existing app should reduce reinventing the wheel and can act as a learning resource. For example, here are two open-source Android bitcoin apps whose source you could grab:
The simplest solution that ...
Its not exactly what you want, http://mycelium.com/ for Android does it the other way around.
You keep your private keys safe in QR-code format on a paper or a offline device, then you scan it when you want to make a transaction. Mycelium signs the transaction and forgets about the key.
I tried to scan with my Android device offline, but it does not work. ...
Just use bitcoind
-walletnotify= Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)
in a script or for more details, access the bitcoind API via RPC https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list
The main issue seems to be a misunderstanding of this message:
"Synchronizing with network, 6 weeks behind."
This indicates that your wallet will be processing transaction data of the last six weeks to ascertain whether any of it is relevant to your wallet. As apparently the Langerhans Dogecoin Wallet is a fork from Bitcoin Wallet for Android, this ...
AFAIU, PoS is considered flawed by large parts of the cryptocurrency community.
I've not kept abreast of POS coins, but some that I could think of are Peercoin, NXT and Blackcoin, which are currently ranked 38, 39, and 58 on Coinmarketcap.
Unless I'm missing some new more popular ones, I'd say there is less software for them because they have less of an ...
Lightweight wallets use a simplified payment verification (SPV) mode which only requires them to download part of the blockchain so yes a full node is required,yes you can clone an existing opensource wallet but skills is required for that
I have the same issue. I used OpenSSL to decrypt the file, gave the correct password and got org.bitcoin.production followed by a load of protobuf-serialized gibberish.
I then processed the output using the tool mentioned here : https://github.com/lloeki/bitcoinj-wallet-dump, which appears to have worked successfully.
It gave me 271 public keys that my ...
This is not possible.
The mnemonic words are an encoding of the entropy used in the seed, essentially. A 12 word seed has less entropy than a 24 word one, so you cannot get 24 words out of it. Similarly, you cannot get a 24 word seed to turn into a 12 word one.
Your best bet is to generate a new 24 word seed and move funds over.