Bitcoin Forum

OK,

The Mycelium server went down a couple hours yesterday so I did not have access to my BTC for a couple hours. This got me thinking.... If thin client wallets' servers go down, will my access to my BTC be lost forever?

If this is not true, then how do I back up my wallets with Mycelium and Electrum so that if their servers go dark (from bankster hackers, government regulators, etc,), I can salvage my BTC with an alternate wallet?


Thanks,
 :)

If they allow you to grab your private keys, then yes you can "salvage" your BTC on another client.

If you don't have access to the private key, you don't own the btc.

This exactly. Another good client that is online (that means it sometimes can be down) is http://blockchain.info (http://blockchain.info)!

Don't leave much coins there for a long time. The same applies for any online wallet. Cold storage is best for large amounts.

http://en.bitcoin.it/wiki/Cold_storage

I have 0.25 in Paperwallets, 0.547 in blockchain and 0.15 in coinbase...

Knowledge of the private keys is what determines ownership of bitcoins. With Mycelium and Electrum the private keys are in your wallet file. With blockchain.info you also have the private keys provided you have a recent backup of your wallet. So with any of these wallets you can access your bitcoins if the servers go down. It just requires some work and technical know how.

Thats a good point to remember.

There are pros and cons to that. With coinbase, you dont have the private keys with you, BUT they pay all transaction fess for you.

Let's get back to the original question ...

Electrum has many servers and anyone can run a server, so a scenario in which no servers are available is unlikely. However, even if you can't access a server, you can still run Electrum and obtain all of your private keys using the console.

Sorry, I don't know anything about Mycelium.

Let me clarify: There is more than one Mycelium server, right now two, and we are expanding as demand grows. It has been a very long time since both servers were down at the same time (if ever). However one of them got stuck recently due to hardware failure, which meant that the node did not receive any blocks. During that time you would not receive any confirmations on transaction sent/received, but you could still spend and see incoming transactions. This only affected Mycelium apps that were connected to that server, and a random one is chosen whenever the app is killed and restarted.

"Keep your private keys private" has been my motto for the last few years in bitcoinland, and the same goes for Mycelium. Your private keys are only on your device, and only leave the device when you choose to...and you should, more coins have been lost due to loss than to theft.

There are two ways for you to get your private keys out of the app. The one that we encourage produces a PDF that contains encrypted private keys, here is a sample (https://www.dropbox.com/s/iau24niy173f7rw/mycelium-backup-12-6-13-2.59-PM.pdf) (without the password). As long as the wallet has a private key that has not been backed up (and imported, to verify that the backup really works) it will show a "Backup Warning" button on the main screen. Annoying but necessary, we really want our users to make proper backups.
 
The other method uses a plain SIPA encoded private key as text and QR code, which is not encrypted, but pretty standard and supported by many other wallets. Access this method by going to the Keys tab, select your key and then the Export option.

Both methods are available even if Mycelium goes bust and the servers shut down.

Thank you for the reply. I did back up my private keys on paper and save it in a safe place but I had no idea what a private key really is (LOL). I only did it to shut up the annoying warning message (double LOL). I think out of all the smart phone wallet apps, Mycelium is the most user friendly due to this simple and almost mandatory paper backup feature.

1. Blockchain; the backup method is easy. You write it down on paper, BUT I don't think that the multiword "seed" are the private keys. If their server goes down, you'd lose your bitcoins unless you can figure out how to backup the private keys. Still trying to figure that one out as a newb....

2. Andreas's Bitcoin Wallet; great app, decentralized with no servers (connected directly to the Bitcoin blockchain) so it won't go dark as easy as other apps that are just thin clients. However, it is not entirely clear if my private keys are backed up. I backed them up and emailed them to myself to save but there's no password so did I just email unsecured and unecncrypted a set of private keys that are unencrypted? The backup process is not very newb friendly.

3. Mycelium is newb friendly with its backup procedure. It is just as easy to use as the other 2 apps for all the other features. It is a thin client so if their 2 servers go down you might temporarily lose access to the bitcoins but that is unlikely. Thanks for letting me know that next time my wallet loses access to the bitcoins, all I have to do is turn off my app and turn it back on again to connect to the  other server. I didn't know that. Thanks.

That is not a backup of your wallet! That is for recovering your password.

To backup your wallet, you choose one of the backup options at the bottom of the main page.