Mycelium Bitcoin Wallet

[madmat]

* Allow spending of unconfirmed funds

Could you give more information on this. I don't understand how it is possible.

It means that you can spend BTC from your Mycelium wallet even if the received transaction has no confirmation.

Ok, but how is it possible ? Bitcoin core doesn't accept transaction if the UTXO are not in a block, so i don't understand how this is technically possible.

When you send a transaction with an unconfirmed UTXO as input, then the unconfirmed UTXO will need to confirm *before* the second transaction get confirmation. So, when first transaction is confirmed, there wouldn't be any problem for second to get confirmation. Do remember that, sometimes, both transactions will be included in same block.

However, if the first transaction is dropped, then miner won't be ableto validate second transaction because input of that transaction doesn't exist and thus, it will be rejected/dropped.

Thanks a lot for this explanation. I didn't know this was possible.

[dooglus]

I occasionally use the Mycelium wallet, but don't really know my way around it. I have a couple of questions:

1) if I want to give addresses to two different people so they can both pay me an amount, how can I do that? The 'receive' button only shows me a single address. It changes as soon as it receives coins, but not until then. So how can I get an address to give to the 2nd person if the 1st one didn't pay me yet?

In bitcoin-core, I would do "bitcoin-cli getaccountaddress "person 2" to get an address to give to person 2. What's the recommended way in Mycelium?

2) possibly related - does Mycelium support the 'payments protocol' thing? I'm not finding anything about it.

[TheButterZone]

Accounts>Add Key>Advanced>Generate new random key

[EcuaMobi]

Accounts>Add Key>Advanced>Generate new random key

Yes for the moment the only way is to use an independent address that needs to be backed up separately. Not being able to have several unused HD addresses is the single reason why I can't use Mycelium as my main mobile wallet, I hope it will be added soon. I can't think of a reason why that would be hard to implement. It just has to scan a few addresses (i.e. 20) and let the user manually enter a higher number if required when restoring a wallet.

I love other features such as being able to sign messages which can't be found on other wallets. It's a shame not being able to use it for the lack of this feature.

[pm7]

It's not the only way. You can also create several HD accounts. Also, Mycelium scan address ahead - you can use xpriv/xpub to generate it.

[RustyNomad]

Have to agree with EcuaMobi that it would be a nice feature to be able to generate more than one new receiving key.

I've also been in a situation where I had to hand out three keys to three separate people and was unable to do so with MyCelium. Ended up giving each person the same key after changing the amount they were to pay a little for each one so that I would be able to distinguish who made a payment and who not.

Another nice to have feature would be the labeling of receiving keys. If you give a key to say 'Joe' you should be able to label the key 'Joe invoice 1098' or whatever.

[dooglus]

Accounts>Add Key>Advanced>Generate new random key

Accounts->Add Key mostly just pops up "Synchonizing, please wait ..." when I touch it. Then the message fades out. But nothing else happens. I wait a while, still nothing happens. I touch 'Add Key' again, and the same thing happens. Eventually, apparently at random, I get to choose between "Add HD Account" and "Advanced".

It looks like "Add HD Account" will let me do what I want. I can add an account for each person I want to give an address to, and name the account after them.

It tells me "All HD accounts are derived from your Master Seed - if you keep your 12-Words-Backup secure, you can restore all your HD accounts with it."

I think "12-Word-Backup" would read better.

To check this, I made a new account, selected it, then clicked 'CREATE BACKUP". We did the "Synchonizing, please wait ..." dance again, and eventually it prompted me for my PIN. I entered it. Then it told me that an additional backupup is currently not possible. And that my PIN was recently changed. That's absolutely not true. I have never changed my PIN since I first set it about a year ago. What's going on there? Why does it constantly try to "synchronize" when I'm not doing anything that should hit the network, and why won't it let me make a new backup? I just wanted to see if it gave me the same 12 words as before, for the new HD account.

Oh, also it says "we prevent you (...) to export ...". To the best of my knowledge, that should be "we prevent you (...) from exporting ...".

[TheButterZone]

Sounds like a clusterfuck of epic proportions for https://github.com/mycelium-com/wallet/issues/new which I can copy and paste and link to if you don't want to submit it yourself.

[birr]

It looks like "Add HD Account" will let me do what I want. I can add an account for each person I want to give an address to, and name the account after them.

It tells me "All HD accounts are derived from your Master Seed - if you keep your 12-Words-Backup secure, you can restore all your HD accounts with it."

By rights, one shouldn't need multiple accounts to generate multiple receiving addresses.
Second and third accounts are meant to enable more than one person to use the same wallet, or for one wallet user to organize the wallet's transactions according to different uses, like a bookkeeping file system.
Forcing dooglus to create new accounts, not because the transactions have different purposes, but simply because the account he's using is limited to a single receiving address at a time, amounts to misuse of bip44's multiple accounts architecture.

If you need more than one receiving address in the same account at the same time, you can generate them yourself:
https://dcpos.github.io/bip39/
Under derivation path -- Mycelium Wallet, m/44'/0'/0'/0
you will see receiving addresses (if you want to see change addresses use bip44 and set m/44'/0'/0'/1).

If Mycelium says your account has let's say 100 private keys, scroll down the derived addresses in the mnemonic code converter until you see the current receiving address.  It will appear before you get to 100 (because change addresses are not shown).
If your current receiving address appears at 53 on the list, you may use addresses 54 and 55 to receive coins...  

Wazrning:  I haven't tried this method yet, so it should be tested with a small transaction to make sure Mycelium doesn't end up garbling transactions somehow.

Edit:  I tested it.  I sent small amounts of xbt to the two addresses (call them B and C) after the current receiving address (call it A).  Mycelium picked up the transactions and updated correctly.  Then I sent xbt to address A, and Mycelium picked up on that as well.
So you can send to addresses before or after the receiving address shown, and everything ought to work.

[molecular]

Accounts>Add Key>Advanced>Generate new random key

Accounts->Add Key mostly just pops up "Synchonizing, please wait ..." when I touch it. Then the message fades out. But nothing else happens. I wait a while, still nothing happens. I touch 'Add Key' again, and the same thing happens. Eventually, apparently at random, I get to choose between "Add HD Account" and "Advanced".

It looks like "Add HD Account" will let me do what I want. I can add an account for each person I want to give an address to, and name the account after them.

It tells me "All HD accounts are derived from your Master Seed - if you keep your 12-Words-Backup secure, you can restore all your HD accounts with it."

I think "12-Word-Backup" would read better.

To check this, I made a new account, selected it, then clicked 'CREATE BACKUP". We did the "Synchonizing, please wait ..." dance again, and eventually it prompted me for my PIN. I entered it. Then it told me that an additional backupup is currently not possible. And that my PIN was recently changed. That's absolutely not true. I have never changed my PIN since I first set it about a year ago. What's going on there? Why does it constantly try to "synchronize" when I'm not doing anything that should hit the network, and why won't it let me make a new backup? I just wanted to see if it gave me the same 12 words as before, for the new HD account.

Oh, also it says "we prevent you (...) to export ...". To the best of my knowledge, that should be "we prevent you (...) from exporting ...".

Just tried to do a backup of my (old) hd account.

Same things happening: "Sorry, additional backup not possible, PIN was recently changed, you have to wait for at least 288 blocks".

I hadn't changed the PIN. I recently updated.

[TheButterZone]

Still not seeing this clusterfuck being posted to https://github.com/mycelium-com/wallet/issues

[Rassah]

You can't generate new addresses because the standard doesn't allow for that. The scan ahead is 20 addresses. We could probably add that feature, but would still have to restrict you to 20 addresses tops (and if you have 20 empty ones every few addresses, it will slow your balance synchronization down). One thing you can do is give someone an address, then create a transaction where you send some money to yourself, which would create a new address, and repeat this for as many addresses as you need. It would just cost you a transaction fee (pick Economic).

[EcuaMobi]

You can't generate new addresses because the standard doesn't allow for that. The scan ahead is 20 addresses. We could probably add that feature, but would still have to restrict you to 20 addresses tops (and if you have 20 empty ones every few addresses, it will slow your balance synchronization down). One thing you can do is give someone an address, then create a transaction where you send some money to yourself, which would create a new address, and repeat this for as many addresses as you need. It would just cost you a transaction fee (pick Economic).

I think 20 addresses would be enough on most cases, I know it would be for me. I'd really like that feature. Anyway the self-sending trick could be used only if more than 20 addresses are required.

I use a different address per transaction and then I can prove the payment wasn't done yet if that specific address doesn't have any transaction. Sending funds to myself to that address could be a problem because the other party could argue they made that payment. I know I could sign from the originating address to disprove it but it wouldn't be comfortable to use this method as standard.

[birr]

You can't generate new addresses

You can generate new addresses, but it's a hassle, because you can't do it in the wallet.  You have to do it on your own.
Of course it would be nice to have that feature in the wallet.  Then someone with a need like dooglus expressed could accomplish that need without using multiple accounts.  It would mean adapting the wallet to show more than one receiving address.
And while we're on the subject of address lists --
Mycelium shows a list of all the HD addresses used in the past, in alphabetical order under the address signing feature.
That's nice, because you can look up an address; but you have to know the address you're looking for.
But if for example you want to see the last three addresses you used, then you won't be able to locate them in the list, because you don't know the addresses, you only know where in the HD sequence (not the alphabetical sequence) they appear.

I would like to be able to see addresses in the signing list chronologically.  And then it would be a simple matter to generate and append several future addresses, which you can copy and transmit to several people at once.  You won't have to serve one customer at a time, or use a different account for every customer.
This would not require any changes to the wallet's main send/receive page.
After receiving funds to addresses that the wallet has not actually generated yet, it might be necessary to refresh the wallet in order to bring it up to date.

[dooglus]

You can't generate new addresses because the standard doesn't allow for that. The scan ahead is 20 addresses.

I usually only need one address at a time, but occasionally I need two. 20 is way more than I have ever needed or can foresee needing.

Is it worth splitting my previous comments up into a bunch of separate github issues, or do the developers read this thread?

[trasla]

Being able to show a second receiving address isnt the big deal - but managing those addresses is. Not because we do not scan ahead, we do that anyway. But how should we know which addresses have been given out to users? You would want to label addresses for expected payments, and be able to mark them as "free" again maybe etc. Maybe showing next five receiving addresses would be okay for some people, but it will be another button potentially confusing people, and then you lose your notes saying which address you gave to whom, and dont know where you should receive next. I am not sure how to implement this best - and between all the nice tasks, have not found time to really think it through.

If someone wants to help, draft a proposal describing how it should be done, and put it up for discussion. If its unproblematic from a usability point of view, I do not see a reason to not implement it.

[EcuaMobi]

Being able to show a second receiving address isnt the big deal - but managing those addresses is. Not because we do not scan ahead, we do that anyway. But how should we know which addresses have been given out to users? You would want to label addresses for expected payments, and be able to mark them as "free" again maybe etc. Maybe showing next five receiving addresses would be okay for some people, but it will be another button potentially confusing people, and then you lose your notes saying which address you gave to whom, and dont know where you should receive next. I am not sure how to implement this best - and between all the nice tasks, have not found time to really think it through.

If someone wants to help, draft a proposal describing how it should be done, and put it up for discussion. If its unproblematic from a usability point of view, I do not see a reason to not implement it.

One option could be:

• On Accounts, user touches the HD Account and on menu there's an option 'Show (unused) addresses'. The list of 5 or 20 addresses is shown.
• User can select an address to copy, share or go to the 'Receiving' screen (where the QR code is shown) with that specific address. They can also hold it and edit its label. To mark the address as free the user can just update the label to blank/null.
• Internally the app would have a SQLite table to store those labels.
• Of course when restoring the wallet from the seed there would be no way to restore the labels. To solve this there can be an option to export labels as json/xml with its correspondent import option. It would use a simple format which just lists the addresses along with the labels.
• There can be an option to store labels on the cloud. While no keys/seeds would be uploaded there could be some privacy issues so this could be off by default.

Let me know if I misunderstood the problem or there are issues on my proposal.

[thorjag]

I have recently installed mycelium on my phone, but am having some issues regarding privacy. I want to restore my old wallet, but before I do I want to enable syncing the wallet via tor. This is not possible AFAIK.

I tried doing a workaround by creating a new wallet, enabling tor and then restoring my backup, but I cannot find any way to restore a backup after I have created a new wallet.

[mattiadeabtc]

there is the possibility ' to have push notifications when you receive bitcoin in your wallet ? i can't see this on settings...

[RustyNomad]

there is the possibility ' to have push notifications when you receive bitcoin in your wallet ? i can't see this on settings...

That will be a nice feature but at present there is nothing like that in the wallet itself. You'll have to make use of a third party service for such notifications.