Bitcoin Forum

Sorry, this is probably really simple, but where is wallet.dat file in Electrum app on OSX (for backup purposes)?

I have checked inside the app ('View package contents') but it's still eluding me...   ::)

Here you can see the location for the electrum.dat

https://en.bitcoin.it/wiki/Electrum#Wallet_File

The windows spec has changed. I need to update that part.

Bah,

I promis the one thing I did before I posted this question was to check the documentation, but dang, I still missed it....

Any chance this could be made into a nice GUI button? Or else, perhaps a copy of it could be sent to a dropbox folder (Blockchain.info's "My Wallet" does this)... Either way, I think a "Backup Wallet" button would be a nice feature.

But BTCVen thanks for quick reply - wallet is now backed-up!  ;D

Although it can't hurt to backup your wallet file it is not needed with Electrum. Just make sure you remember your seed and you can always restore it when something goes wrong. The Lite GUI has a menu options called "Create wallet backup".

Ok thanks Tachikoma, (I have not tried the Lite menu yet - are you sure that is for OSX too?) but I have imported some additional private keys into that walleet (including a vanity address) which will not be restored from seed regeneration, and I'm sure I will not be the only one doing this.

I still maintain that it would be good to have an encrypted wallet backup button, to let people take control of their own wallets... what happens if Electrum's servers all go offline or something (OK slim chance maybe but what if?) are you able to restore your Wallet on your own using the seed phrase? Perhaps the code to translate the seed phrase is available in github (haven't checked), just something to consider I suppose...

If all servers go offline you can still generate your addresses via your seed. I am sure the backup function works on OS X since I build it on there ;)

I really don't see the sense in vanity addresses, I rather have all my adresses backed up then relying on wallet.dat files.

Tachikoma, right you are about the backup function - I had the client in advanced mode thinking I was all advanced, but it was staring me right in the face in simple mode!!

Not sure what you mean though that you like having your addresses backed up rather than relying on wallet.dat files? I thought the wallet.dat was a single file which was just a collection of all your addresses (and their corresponding key pairs), or have I got this wrong again?

Thanks for the build though, good work!

No you are right about that. I just don't use vanity keys myself since I can't guarantee my hardware will never crash. I rather not use vanity keys and rely on my seed. That's just personal preference though :)

I've just been checking out electrum for the first time as there has been a little too much security talk around blockchain.info recently and so I wanted to make a true offline wallet.

How do I create and keep an offline wallet without it ever touching the online world presumably something like the following.

• I was hoping to create my offline wallet in and an encrypted .sparsebundle .dmg
• make transactions offline
• eject the .dmg and hence the wallet
• then go online so that the transactions would update.

Thinking about this outloud I realise that without a copy of the blockchain locally this is probably not possible?? maybe using two computers??

Am I missing something? Can I create a pure offline wallet in electrum or would I need to use armory or similar to do this?

if it is not possible how am I any more secure with electrum than say blockchain.info?

I will write this down one day because I have written it out a couple of times now but this is how I deal with offline transactions.

1. Get an offline computer. This can be a physical device or a separate installation on your current computer. I would advice a Debian installation with encrypted home folder for extra security.
2. Boot / Start your offline installation and install Electrum via a USB-Key.
3. Create a new wallet on the offline computer. Write down the seed and memorize it, after which you should probably destroy the seed or keep it safe in a lockbox.
4. Go to settings->Import/Export and copy your "Master Public Key" and put it in a text file on your USB-Key.
5. Reboot to your online installation.
6. Install Electrum and restore a wallet, use the "Master Public Key" and let it run.

You know how an online wallet where you can check your balances and give out new addresses, but you can't however spend the coins. So if an attacker would be able take over your online computer your coins can't be lost.

To make a transaction do the following:

1. Go to the send tab like you normally would and make a transaction. Instead of sending it it will detect a seedless wallet and query for a location to save the transaction. Select your USB-Key.
2. Reboot your computer to the offline installation.
3. Boot electrum and go to settings->import/export -> "Load raw transaction". Select your transaction from the USB-Key. It will detect it's not signed and will prompt you to do so now. Fill in your password and sign the transaction. Save the new, signed, transaction to your USB-Key.
4. Reboot your computer to the online wallet and boot Electrum.
5. Boot electrum and go to settings->import/export -> "Load raw transaction". Select the signed transaction and it will ask you if you want to broadcast it. Do that and you should be done!

I will take some time later to add some screenshots and fix it up so I can add it to electrum.org I guess this question should be answered there.

Yes, please put this on the website. . . It is very helpful.

On the way ;)

Check http://electrum.org/tutorials.html#offline-mpk when updated

I've already written the article I just need to translate it to English. Should be finished next week :)

Tachikoma: You have explained how to send BTC from the offline computer; but how do you receive BTC to the offline computer?

Simple, just start it on your online system using the master public key and send to an address there.

Guys.. just a little re-assurance. Im a long time QT user thinking to switch to Electrum.. been researching for a while now. So it seems I don't have to make scheduled backups of my wallet with Electrum (as I currently do with QT) at all. As long as I remember the generated seed to memory perfectly, thats all I will EVER need to rebuild my wallet and use spend my BTC in any scenario (other someone stealing my seed), correct?

With QT now, the syncing with the blockchain, plus issues since I'm on OSX (random crashes and having to rebuild the block database or re-sync etc) has made me very paranoid and I've started backing up my encrypted wallet to external storage. It seems like Electrum would be an elegant alternative, with no need to download the entire blockchain and in the event I have to access my wallet on a new computer (or alternative machine of my own), I wont have to wait a day.. it's download Electrum, re-create from Seed, and boom. Is this correct?

For added security, it allows the current wallet to be encrypted as well (but if I'm understanding correctly, once you recreate a wallet from a seed, the 'encrypted' part of it goes out the window and you must now re-encrypt otherwise the wallet is wide open to spend with, yes?)

And in the unlikely event the Electrum servers all go down forever.. I would still be able to re-create my wallet from my seed? Where? And more importantly, where would my private keys be if that has to be the case?

A little help from fellow Electrum OSX'rs would be awesome.. especially since it's a big switch and one always gets paranoid when trusting a new "place" with your money  :)

FYI - Im on OSX Mavericks, and would be installing Electrum 1.9.4 (NOT 1.9.5 since I understand there are some issues with OSX and that version still being hammered out), and I'm also not too keen on offline paper wallet super cold storage either since I'm pretty secure (firewall, filevault, encrypted volumes etc).

So.. yes? Send my BTC from QT over to Electrum in 1 swoop and never look back? Or nay?

Thanks guys!

In order,

Correct, correct, correct, yes, using the program or the code from github or an application like carbonwallet.com, the same private keys can always be regenerated using the technique used by electrum but as long as the project exists on github you will be fine, Yes send them over but make sure to memorise that seed!!

Only if you have imported keys you'll need a backup of the wallet file, if not, you have enough with the seed.