Mycelium Bitcoin Wallet

[apetersson]

v2.1.0-BETA1 has been pushed to github and the beta channel.

changes:
preview of secret sharing import/cold storage
optimized output selector that omits dust from transactions and makes fees smaller on average
fallback geocoder
new nfc function to push payment request
show total amount of coins in accounts view
customizable fees
pin reset function - if you forgot it
fix crash if you don't have a flash on your device
removed obsolete mbwapi binary interface

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[pm7]

3.   NFC Pay tapping - 1 Tap = 1 Pay

Not possible. At least not with one tap. You need 1 tap to request the address and amount to send to, then the wallet signs, and then one more tap to send the signed transaction. The reason 1 Tap = 1 Pay works with credit cards is because it's the equivalent of tapping to give the merchant your private key, and then having them only pull out what they need.

Why to send signed transaction by NFC instead releasing it directly to Bitcoin network by smartphone's Internet connection?

[Zelig]

Is it supposed to create a new private key each time I open the wallet?  Or, I don't know if it's each time, but I have about 15 private keys already.  Why isn't one private key enough? 

The HD account creates a new private key and address every time you receive coins (new receiving address) and every time you send coins (new change address).
This improves your privacy, because some sending money to you or getting money from you cannot easily see your complete past transaction history.

Thanks!  I knew it was supposed to create new public keys, but wasn't sure about private.

Z

[OnkelPaul]

Hi,
after updating, Mycelium tells me that my Android 2.2 phone is unsupported due to a bug in random number creation on that OS version.
Could you share some technical details so I can estimate my risk? (or did I miss an announcement somewhere?)
Since I'll be switching to a new phone in a few weeks anyway (Christmas is just around the corner) I could probably live with avoiding to create new transactions and just initializing from the backup once I have the new phone.

Onkel Paul

[apetersson]

Hi,
after updating, Mycelium tells me that my Android 2.2 phone is unsupported due to a bug in random number creation on that OS version.
Could you share some technical details so I can estimate my risk? (or did I miss an announcement somewhere?)
Since I'll be switching to a new phone in a few weeks anyway (Christmas is just around the corner) I could probably live with avoiding to create new transactions and just initializing from the backup once I have the new phone.

Onkel Paul

there is a bug that leads to android 2.2 being unable to multiply big numbers _sometimes_. previously this mostly just lead to wrong TX being generated, that were rejected by the network. annoying, but no huge risk.

now with HD wallets it is possible to generate a wrong address from a seed that has no matching private key. this is bad. therefore, quit using it we had one case where a user reported this, and we strongly think android 2.2 was the reason.

[OnkelPaul]

Ah, ok, this is indeed bad, thanks for the explanation!
So as upgrading the OS is not an option (Samsung isn't really eager to supply updates, and the phone isn't really supported by Cyanogenmod), I'm just waiting for the new phone. Whatever transactions I need to do in the meantime can be done with bitcoin core on my desktop.

Onkel Paul

[paullinator]

3.   NFC Pay tapping - 1 Tap = 1 Pay

Not possible. At least not with one tap. You need 1 tap to request the address and amount to send to, then the wallet signs, and then one more tap to send the signed transaction. The reason 1 Tap = 1 Pay works with credit cards is because it's the equivalent of tapping to give the merchant your private key, and then having them only pull out what they need.

Why to send signed transaction by NFC instead releasing it directly to Bitcoin network by smartphone's Internet connection?

You are right. You can do 1 device-to-device tap to pay as long as the Sender is broadcasting out the message directly to the network using their internet connection. Another way is to use both NFC and bluetooth (BLE) and tap to get URI and BLE communications key via NFC, then use BLE to talk to device and send Tx after.

Airbitz actually has the one tap method functional in our next release which should be out this week. Here's a video of it working

http://youtu.be/kmksAu_ytMg?list=UUJaTFo0_z9lEG_v7L_LT2pw

[hgmichna]

I would like to put a bitcoin address up on a web site for donations (and later change it from time to time). How can I do this with Mycelium? How can I create a new bitcoin address, either HD or non-HD, for this purpose?

My HD wallet already has several bitcoin addresses with zero bitcoins on them, and one possibility would be to use one of them. But Mycelium does not seem to display them. But even if I wanted to create a new non-HD wallet/address, I cannot find any way to do that with Mycelium.

I have not considered creating multiple HD wallets, because I thought that too unwieldy and impractical. I don't even know whether that would solve the problem.

What would be the most elegant way to do it?

[trasla]

You cannot create new single addresses, just import them, because random single keys would not be backed up by your wordlist backup, and we want to prevent users from loosing money.

Your could just put up the current receiving address of your HD account.
As soon as you receive money to it, the app will display a new receiving address, but the old one will still work.
You can then replace the address with the new current one whenever you want to.

You could of course also create a new HD account, and use that one only for website donations, and replace the address with that accounts receiving address from time to time.

[hgmichna]

Thanks, that sounds feasible. Will try the current HD address.

[Rassah]

3.   NFC Pay tapping - 1 Tap = 1 Pay

Not possible. At least not with one tap. You need 1 tap to request the address and amount to send to, then the wallet signs, and then one more tap to send the signed transaction. The reason 1 Tap = 1 Pay works with credit cards is because it's the equivalent of tapping to give the merchant your private key, and then having them only pull out what they need.

Why to send signed transaction by NFC instead releasing it directly to Bitcoin network by smartphone's Internet connection?

Mycelium already supports this. The idea was to be able to use your phone to pay with bitcoin, using the merchant's connection to the bitcoin network, without the user even needing a data connection (for example if you don't have a data plan, have bad reception, or are traveling outside of your coverage area). This would need NFC for the merchant to send the request, and NFC or bluetooth (though bluetooth isn't typically available in payment terminals) to receive the signed transaction back.

[molecular]

Electrum does not use BIP39. They have their own custom word list, as does DarkWallet which is trying to be compatible with Electrum. Anything that IS compatible with the BIP39 standard will let you import the coins (such as a Trezor). Electrum claimed they will move to BIP39 eventually, but I don't know when.

I'm not 100% sure, but I think the move to BIP39 is in the upcoming 2.0 release (that also supports trezor).

[ZephramC]

Hi,
after updating, Mycelium tells me that my Android 2.2 phone is unsupported due to a bug in random number creation on that OS version.
Could you share some technical details so I can estimate my risk? (or did I miss an announcement somewhere?)
Since I'll be switching to a new phone in a few weeks anyway (Christmas is just around the corner) I could probably live with avoiding to create new transactions and just initializing from the backup once I have the new phone.

Onkel Paul

there is a bug that leads to android 2.2 being unable to multiply big numbers _sometimes_. previously this mostly just lead to wrong TX being generated, that were rejected by the network. annoying, but no huge risk.

now with HD wallets it is possible to generate a wrong address from a seed that has no matching private key. this is bad. therefore, quit using it we had one case where a user reported this, and we strongly think android 2.2 was the reason.

Mycelium warned me that there will be no further updates for my Android version.
So using Mycelium HD wallet functionality with this old Android is not recommended now? I can use old pre-HD address pairs.

[trasla]

We only strongly advise against 2.2, that's why there is a big red warning. Other old versions get a notification that we will not put out updates for them (we will of course if we encounter critical bugs).
It's perfectly fine to continue using them including all features and HD. Our new releases will only support newer versions of Android, because it will be easier to code, work better, requires less permissions etc.

[testconpastas2]

will coincontrol soon be released? or  is it down on the list?

Any official roadmap link with the next features sorted by priority?

Thank you.

[Rassah]

will coincontrol soon be released? or  is it down on the list?

Any official roadmap link with the next features sorted by priority?

Thank you.

Coincontrol is not on our todo list. Our wallet is meant for personal daily usage, and automatically picks which addresses to spend from to minimize fees. Once we implement CoinJoin, coin control may even be a security issue that could expose the privacy of your addresses.

Here's the roadmap so far:

Allow lower transaction fees (currently in beta)
Support for Shamir's Secret Sharing keys, which are private keys that are split into m-of-n parts, as supported by Mycelium Entropy (currently in beta)
BitID support (currently in testnet)
Support for tor through nodes accessible over tor hidden services (implemented and being tested on the nodes)
Added functionality to LocalTrader, such as more control over trading logs, and improved reputation options, including reputation for buyers so they can be trusted to buy from sellers using more risky means.
More selling options on LocalTrader besides just bitcoin for fiat, such as bitcoin for other stuff you want to sell, similar to Craigslist
Support for CoinJoin (possibly later this Spring)
Support for Rivetz (when their API comes out in 2015)
Implement BIP70 (it's a constant medium-to-high priority that we just can't set aside the time to do)
Possibly support for other digital currencies
Long term, we hope to make Mycelium into a full fledged financial app, with support for transaction categories, exporting transaction history, monitoring spending, being able to use is as a merchant POS, etc.

[testconpastas2]

Very nice
Eagerly awaiting...

Thank you

[Newar]

Over in the localbitcoins.com thread there is a report that users from Germany are barred (I'm guessing by using IP geolocation) from using the service since the money flow can not always be traced (cash deals). Has Mycelium been approached by regulatory authorities from Germany? What do you think about it?

[trasla]

We have not been approached by authorities thus far, and suspect they don't even know about us.
The situation might be different, since we do not hold user funds.
For now, no immediate action / changes will take place, but we will monitor what happens...

[bitcats]

We have not been approached by authorities thus far, and suspect they don't even know about us.
The situation might be different, since we do not hold user funds.

That makes the crucial difference!