i can understand the ability to make a brainwallet with electrum and iits remembering the 12 words seed but kinda sucks because words are made by the wallet and your self .
i see a lot of people speaking about brain wallet , basically if i want to make one how i will do that exactly ?? if i have wallets like bitcoin core , multibit etc ... ? pretty sure it's all about remembering the passphrase but those haven't unless you mean the password that helps you to send coins
Brainwallets are in general a very bad idea.
The main reason is that is very very difficult that you can come up with a sentence you can remember and that software built on purpose cannot guess.
That said. If:
- You have a sentence made of AT LEAST 15 words
- ISome of these words have no sense for anyone in the world except you
- This sentence contains any kind of special character like& ( ] # £" ./ and so on
- It contains numbers as well
- This sentence or even a close one cannot be found searching of the internet with google or whatever else
IMHO you can try to play with it. After all the concept behind brainwallets is so fascinating I would personally risk
some spare cash to learn.
Being able to carry some emergency "argent de poche" everywhere in the world is really appealing. It make you feel "007" (even if you are risking)
Just remember no expert will tell you ever this is a good idea. And the reality is often worse than your worst expectations.
But how can I build a brainwallet?The easiest way is to put your sentence in a saved offline version of bitaddress.org, to send some funds (very few) to the generated address and delete everything in the safest way possible.
When one day you need cash you can regenerate the private key by doing a sha256 on the original and sentence (better offline) and swiping the generated private key (the result of the hashing operation) onto you mobile bitcoin wallet.
It is important to swipe your private key and not to import it because you take down the risk a little bit.
But is it safe?Once again no. But done properly can be not so dangerous and can be ok for experiments with little amounts and can teach you something about the actual functioning of bitcoin.
Is there something else I can do?Yeah. I'm fascinated by the possibility to create a BIP32 wallet from a "brainseed".
I mean you can apply a SHA512 to your sentence and make it the seed for your BIP32 wallet.
In this way you can store amounts of bitcoins in many addresses and regenerate any of them when you need.
Again this a good way to learn by doing how BIP32, private keys and addresses work but it is not safe for your funds. I would use this just to learn exciting things and I would consider loosing the entire amount a fair cost for the fun.
With a couple of dollars you can pay yourself a lot of fun.
But what is the difference with the 12 words sentence Electrum gives you?Electrum sentence is derived from a big number generated with the best technology for randomness available at that scale. It is orders of magnitude more unguessable than the sentence you can came up with.
If you have good memory is much more practical to memorize the sentence and to type it into a clean offline copy of Electrum each time you want to use the bitcoins. But for this approach to be safe it is better you keep a deseeded copy of your wallet on a connected computer and that you type your memorized seed on an offline copy of Electrum only when you want to sign a transaction.
