How I recovered my (sort of) lost encrypted wallet on bitcoin-qt client S/W

PeterB

full member

Activity: 168

Merit: 100

Quote from: Foxpup on April 21, 2013, 09:57:35 PM

Quote from: ?? on ??

Not a risk if you keep that original wallet.dat file offline, on a separate dedicated USB thumb drive. And another for good luck in a different location!

You can now encrypt without fear of losing BTCs.

This is just plain wrong. This is probably the riskiest thing you can do with Bitcoin (besides use an unencrypted wallet with no backups). If you do this, you almost certainly will lose money, one way or another. There are two different ways you can lose money by doing this. First, and most obviously, anyone who gains access to one of your unencrypted backups will be able to steal your bitcoins.

Second, if you create a new address in your encrypted wallet (which, for technical reasons, also happens every time you send bitcoins), this new address will not be present in your backup wallet. Normally it would be, as the wallet generates 100 addresses in advance for exactly this reason (you can create up to 100 new addresses and they'll all be present in your backup, so you don't have to worry if your backup is a little bit out of date), but encrypting your wallet deletes these unused addresses and creates 100 new ones, to minimise the amount of money you stand to lose if a previous unencrypted backup gets stolen (ideally, it would delete all your address and replace them with new ones, but it can't delete the ones you're already using, because, well, you're using them). If you send bitcoins using your encrypted wallet, or create new addresses in your encrypted wallet, your unencrypted backup will not be able to recover all your bitcoins.

You have been warned.

Thanks for this.

saurey

newbie

Activity: 6

Merit: 0

Equal security risk - forgetting your password and not having a backup. That's like having a pile of gold bars in a case made of unobtanium. You have the gold but you can't get to it...

Happened to me today lost 50+..

umairsaleem007

newbie

Activity: 6

Merit: 0

Thanks for the info.

tlhonmey

newbie

Activity: 37

Merit: 0

It's not that big a security risk as long as you scrub the unencrypted wallet off of the drive (there are utilities for both Windows and Linux that will do this.)

You will run into trouble, however with the fact that the default wallet is only 100 addresses.

So, what I do, is use the bitcoind program's command-line option to increase the key pool size to a ridiculous size (say 400,000). It will take a considerable amount of time to generate a wallet this big, but it will also take a long time to go through that many addresses. It should just fit on a CD. Create a CD iso image with the file and enhance it with DVDisaster for extra protection against degradation. (You can find DVDisaster via google.) Store it somewhere safe. Like in your fire safe. Then encrypt your wallet and scrub your drive. When you get close to using up all the addresses, make a new wallet. (But it will take a while with that many addresses.)

anderl

hero member

Activity: 714

Merit: 500

this is a major security risk. If you ever sell the computer you have your wallet on it wouldn't be too hard to recover the data off the drive that the dat file was on. If it wasn't encrypted I could just recover the file catch it up to the network and transfer all your coins from your account.

This is a warning to everyone, physically destroy your hard drives. A data wipe may not be enough. If you do loose your wallet or your computer Immediately transfer your coins from it otherwise you run the risk of losing it all.

Foxpup

legendary

Activity: 4542

Merit: 3393

Vile Vixen and Miss Bitcointalk 2021-2023

Quote from: ?? on ??

Not a risk if you keep that original wallet.dat file offline, on a separate dedicated USB thumb drive. And another for good luck in a different location!

You can now encrypt without fear of losing BTCs.

This is just plain wrong. This is probably the riskiest thing you can do with Bitcoin (besides use an unencrypted wallet with no backups). If you do this, you almost certainly will lose money, one way or another. There are two different ways you can lose money by doing this. First, and most obviously, anyone who gains access to one of your unencrypted backups will be able to steal your bitcoins.

Second, if you create a new address in your encrypted wallet (which, for technical reasons, also happens every time you send bitcoins), this new address will not be present in your backup wallet. Normally it would be, as the wallet generates 100 addresses in advance for exactly this reason (you can create up to 100 new addresses and they'll all be present in your backup, so you don't have to worry if your backup is a little bit out of date), but encrypting your wallet deletes these unused addresses and creates 100 new ones, to minimise the amount of money you stand to lose if a previous unencrypted backup gets stolen (ideally, it would delete all your address and replace them with new ones, but it can't delete the ones you're already using, because, well, you're using them). If you send bitcoins using your encrypted wallet, or create new addresses in your encrypted wallet, your unencrypted backup will not be able to recover all your bitcoins.

You have been warned.

vm1990

legendary

Activity: 1540

Merit: 1002

depends where you keep it i keep an unencrypted version of my wallet.dat on a pen drive

Stoneysilence

member

Activity: 104

Merit: 10

Quote from: old c coder on April 21, 2013, 12:37:28 PM

Hello

I have bitcoin-qt version 0.8.1 (running on windows) and before encrypting the wallet, I had made backups of the wallet.dat file. Then sometime later I encrypted the wallet and wrote down and copied and pasted, I swear, to the wallet input form to encrypt. Never checked it, since I had no need to send BTCs anywhere.

Then I acquired some BTCs and tried to create a second address in the wallet, which required entering the passphrase. No luck, it kept saying wrong passphrase. And now I couldn't send the BTCs either! I tried various near combinations, etc. no luck. I could see the transactions that put coins in, but I couldn't get them out!

I tried various backups of the encrypted wallet, that I had made with each deposit of BTCs. No luck on any of them.

I then tried a wallet.dat backup from before I had encrypted it. Lo and behold, bitcoin-qt read the deposits from the blockchain (I presume?) and restored my now old unencrypted wallet to the current correct amount. And now I am able to send BTCs, etc.

So if you have an old wallet.dat copy from before encrypting, you might try that! Hope it works.

Ron

Nice to know but that also means it's a security risk.

old c coder

sr. member

Activity: 260

Merit: 251

Hello

I have bitcoin-qt version 0.8.1 (running on windows) and before encrypting the wallet, I had made backups of the wallet.dat file. Then sometime later I encrypted the wallet and wrote down and copied and pasted, I swear, to the wallet input form to encrypt. Never checked it, since I had no need to send BTCs anywhere.

Then I acquired some BTCs and was unable to create a second address in the wallet, which required entering the passphrase. No luck, it kept saying wrong passphrase. And now I couldn't send the BTCs either! I tried various near combinations, etc. no luck. I could see the transactions that put coins in, but I couldn't get them out!

I tried various backups of the encrypted wallet and these also failed, that I had made with each deposit of BTCs.

My only recourse was to try a wallet.dat backup from before I had encrypted it. Lo and behold, bitcoin-qt read the deposits from the blockchain (I presume?) and restored my now old unencrypted wallet to the current correct amount. And now I am able to send BTCs, etc.

Ron

Topic: How I recovered my (sort of) lost encrypted wallet on bitcoin-qt client S/W (Read 1143 times)