Quote from: aerobatic on February 13, 2016, 10:50:53 PM

Quote from: marbu1022 on February 13, 2016, 08:17:20 PM

I don't see how it's possible to crack such a sophisticated password as what you say you used. You are talking about a 256 bit + password. This password cannot be cracked in any practical amount of time.

marbu -

there's several attack vectors to worry about when using brain wallets, which aren't a worry when using other types of wallet.

for instance. every time you need to type it out, to get it converted back into the private key... it could be intercepted locally on your computer using spyware or a key logger. it could be intercepted using man in the middle attack on your internet connection or your wifi via a network sniffer or via a mitm ssl attack. it could be intercepted at the web site that you're using to generate the brain wallet key in the first place. or your java installation etc. it could be a corrupt brain wallet generator. or one with a weakened rng seed... etc. there's too many attack vectors to think that brain wallets are a safe way of storing your bitcoins. you are very reliant on a lot of things not being hacked, for you to continue to use a brain wallet. anytime, during creation or use, or even just doing nothing, can be a risk factor. Even Entropy checkers that are on the internet, could potentially be logging your passwords, and populating similar words into their dictionary with your entropy test results, so that the hackers have a better understanding on what kind of passwords people use (!)

i counted the letters in the brain wallet i was referring that got hacked, and to make a correction, it was less than the 40 chars i said it was - just to be accurate, it was 34 characters. sorry, i thought it was more.. but the point was, it was still a long string of letters and numbers, some of which were words, some caps, some punctuation, and it still got hacked. whether it was hacked with brute force from a cloud password generator or some other weak point in the brain wallet system, i really don't know. All i know is that the ONLY loss i have ever had from any bitcoin wallet... was from a brain wallet. Ive not even (touch wood) lost anything from web wallets like Blockchain.info (and nowadays I've migrated to a hardware wallet and cold storage, as i don't even trust paper wallets as they have some of the same attack vectors to brain wallets)

aerobatic,

Any time that you send btc from a wallet, you are subject to the possibility of someone stealing your private keys, which are what is necessary to take over the wallet and remove all funds. The use of any wallet involves the use of encryption. Encryption is a tool that must be used properly, or just like any other tool, you can end up hurting yourself or others. I suggest you read up on managing encryption passwords and keys.

The information that you provided, as far as the different attack vectors that brain wallets are subject to, also applies to other wallets. I dispute, however, your claim, that brain wallets should never be used.

Going back to your case scenario, where you stated, that you had a 34 character password with characters and symbols, one can only conclude, that your password was stolen by some means; a key logger, or a different type of malware. Again, it is highly unlikely that your password (as you describe it) was brute forced, therefore I have to conclude that you completely mismanaged your wallet.

There are many ways of generating secure, brain, and other types of wallets. One would be by employing the use of a "live" and offline operating system using a reputable wallet, such as electrum. Once your wallet is generated, you can write down all of your public addresses, memorize your seed, (you should develop a way to get at your seed in case you forget it) and then take the wallet offline, where it can remain in cold storage for a very long time. This method would likely be very safe. The amount of security you should employ depends on the amount of funds that you are trying to protect. People will be willing to work a lot harder to get at something that is worth a lot to them. Keep in mind that the physical security of the device you are using to store your wallet (e.g. computer, tablet, phone, hardware wallet, etc...) is very important.