<p>Blockchain.info's My Wallet stores your Bitcoin wallet in encrypted form. This means that anyone that knows your wallet identifier can retrieve the encrypted form of your wallet. One can of course only use/open the wallet with the encryption password.</p>

<p>This does however mean that anyone that retrieved your wallet identifier can try to guess your password as many times as they want. Once they got the encrypted version of your wallet, they can use smart brute force techniques to crack your password.</p>

<p>So, you could have been hacked if both</p>

<ul>
<li>Someone got hands on your wallet identifier. Maybe you mailed it or mentioned it somewhere. Maybe you got malware or a spoofing browser extension.</li>
<li>You have a weak password so that regular password crackers were able to find your password fairly easily. Try to avoid passwords consisting of only existing words or only lower case characters f.e.</li>
</ul>

CC BY-SA 3.0
2013-04-27T10:48:42.413Z
2013-04-27T10:48:42.413Z
Steven Roose
<p>I have a blockchain.info wallet. Last night I decided to set up a wallet for my daughter so I signed out of my account. Created one for her and then had difficulty signing in to mine, I had about 8 attempts then gave up. I then noticed in my email I had an email from blockchain telling me of each of the failed attempts which was me. I then managed to get into my wallet and 99% of my BTC had gone. Is this a security feature or has someone stolen them? Thanks. I have checked the new wallet in case they were there but sadly they are not.</p>

CC BY-SA 3.0
2013-04-27T10:30:04.877Z
By blockchain, are you referring to blockchain.info? How secure of a password did you set on the first account?
Nick ODell
CC BY-SA 3.0
2013-04-28T14:52:04.680Z
Have a look at the transaction history for the relevant addresses - when were the coins transferred away?
George Pearce
<blockchain.info>
Lost my BTC or they've been stolen
Mike
# Lost my BTC or they've been stolen

(Asked by: username_0 on 2013-04-27)

I have a blockchain.info wallet. Last night I decided to set up a wallet for my daughter so I signed out of my account. Created one for her and then had difficulty signing in to mine, I had about 8 attempts then gave up. I then noticed in my email I had an email from blockchain telling me of each of the failed attempts which was me. I then managed to get into my wallet and 99% of my BTC had gone. Is this a security feature or has someone stolen them? Thanks. I have checked the new wallet in case they were there but sadly they are not.

**Tags:** blockchain.info

> **Comments:**
> **username_1**: By blockchain, are you referring to blockchain.info? How secure of a password did you set on the first account?  
> **username_2**: Have a look at the transaction history for the relevant addresses - when were the coins transferred away?  

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## 1 answers

### Answer by username_3 on 2013-04-27. Score: 1

Blockchain.info's My Wallet stores your Bitcoin wallet in encrypted form. This means that anyone that knows your wallet identifier can retrieve the encrypted form of your wallet. One can of course only use/open the wallet with the encryption password.

This does however mean that anyone that retrieved your wallet identifier can try to guess your password as many times as they want. Once they got the encrypted version of your wallet, they can use smart brute force techniques to crack your password.

So, you could have been hacked if both

* Someone got hands on your wallet identifier. Maybe you mailed it or mentioned it somewhere. Maybe you got malware or a spoofing browser extension.
* You have a weak password so that regular password crackers were able to find your password fairly easily. Try to avoid passwords consisting of only existing words or only lower case characters f.e.


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