How to make brainwallet ?

[The Bad Guy]

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

[el kaka22]

If you are going to make a brain wallet, make sure it contain some meaningless characters in the passpharse (or someone may guess the wallet).
You can go to various websites to generate a brain wallet like bitaddress.org. It will work like a paper wallet.

[shorena]

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

Memorize anything you want to use as a brainwallet, convert it in a repeatable way to a number that would serve as a private key (between 0x1 and  0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140)[1] and calculate the address[2]. Done.

The problem is that humans are very bad at picking random things. We think when we smash our face at the keyboard is random, but its actually pretty predictable what will happen. Thus a brainwallet based on electrum is actually a better way than to do it yourself. If you want some ideas how to create a brainwallet with sufficient entropy I suggest this[3] thread.


[1] https://en.bitcoin.it/wiki/Private_key
[2] https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses
[3] https://bitcointalk.org/index.php?topic=885616.0

[The Bad Guy]

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

Memorize anything you want to use as a brainwallet, convert it in a repeatable way to a number that would serve as a private key (between 0x1 and  0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140)[1] and calculate the address[2]. Done.

The problem is that humans are very bad at picking random things. We think when we smash our face at the keyboard is random, but its actually pretty predictable what will happen. Thus a brainwallet based on electrum is actually a better way than to do it yourself. If you want some ideas how to create a brainwallet with sufficient entropy I suggest this[3] thread.


[1] https://en.bitcoin.it/wiki/Private_key
[2] https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses
[3] https://bitcointalk.org/index.php?topic=885616.0

say what , so basically the adress is generated from the random words ? same goes private keys ? are those actions reversible ? means someone with the pass can guess adress , and someone with adress can get your password  ( which sucks) ?

[cakir]

Brain wallet = human memory.
Think about something (easy to remember but hard to predict which has to be meaningless)
For instance: "alice gone to barber shop to drink coffee"
Then use this page; https://brainwallet.org/#generator (You can download it and use it offline, it's coded in JS so it works client side).
For our example our public address is: 19JKY4xxx8hveoXp6nucHPQ6ayu2EqtAVY and it's  WIF priv key is: 5KF4m3tGeV5BfQFFmm7RUzmcgmAMA5WW23Bru22J98rSgfNrZFM

Ps: do not use known catchphrases like "to be or not to be" https://blockchain.info/address/1J3m4nneGFppRjx6qv92qyz7EsMVdLfr8R

[virtualx]

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

Brain wallets are just a series of letters that is used as input for an SHA-256 hashing function. The hash is then used to generate the private key and bitcoin address.
Simplified:  these words are used to control a bitcoin address.

Here is a simple code:

Code:

from bitcoin import *
priv = sha256('a brainwallet password from the bad guy')
pub = privtopub(priv)
addr = pubtoaddr(pub)

addr will then be your bitcoin address. The passphrase is used to generate the private key. Private keys control the bitcoins. If you choose a bad pass phrase, your bitcoins are gone.
You can generate brain wallet from command line, the web or a wallet.

[shorena]

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

Memorize anything you want to use as a brainwallet, convert it in a repeatable way to a number that would serve as a private key (between 0x1 and  0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140)[1] and calculate the address[2]. Done.

The problem is that humans are very bad at picking random things. We think when we smash our face at the keyboard is random, but its actually pretty predictable what will happen. Thus a brainwallet based on electrum is actually a better way than to do it yourself. If you want some ideas how to create a brainwallet with sufficient entropy I suggest this[3] thread.


[1] https://en.bitcoin.it/wiki/Private_key
[2] https://en.bitcoin.it/wiki/Technical_background_of_version_1_Bitcoin_addresses
[3] https://bitcointalk.org/index.php?topic=885616.0

say what , so basically the adress is generated from the random words ?

Well indirectly yes. A brainwallet is a way to memorize a larger number that represents your private key. The private key is tied to a certain address as the address is calculated from it.

same goes private keys ? are those actions reversible ?

No, they are not reversible. The private key has a corresponding public key. If you spend coins the public key gets known. It is to our current knowledge not possible to calculate a private key from a public key. You would have to brute force it and due to the larger numbers thats not possible either. If you never spend any coins the public key is not known and your private key is also protected by the hash functions used, which are also not reversible. Hash functions are also considered to be quantum secure.

means someone with the pass can guess adress , and someone with adress can get your password  ( which sucks) ?

If anyone should guess your passphrase and the way you convert it to a number they have your private key and can spend your funds. Thats why its so important to use something random and not something like a quote from your favorite book. It is not possible to get the private key from your bitcoin address.

Brain wallet = human memory.
Think about something (easy to remember but hard to predict which has to be meaningless)
For instance: "alice gone to barber shop to drink coffee"
Then use this page; https://brainwallet.org/#generator (You can download it and use it offline, it's coded in JS so it works client side).
For our example our public address is: 19JKY4xxx8hveoXp6nucHPQ6ayu2EqtAVY and it's  WIF priv key is: 5KF4m3tGeV5BfQFFmm7RUzmcgmAMA5WW23Bru22J98rSgfNrZFM

Ps: do not use known catchphrases like "to be or not to be" https://blockchain.info/address/1J3m4nneGFppRjx6qv92qyz7EsMVdLfr8R

Or the famous "correct horse battery staple"[1] brainwallet -> https://blockchain.info/de/address/1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T

[1] https://xkcd.com/936/

[LiteCoinGuy]

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

dont do it. buy a hardware wallet:

https://bitcointalk.org/index.php?topic=899253.0

[The Bad Guy]

@virtualx & Shorena , thank you so much for your help it's really helpful at least know I understand how all those words (didn't wanna quote so I don't get a 2km reply )

@LiteCoinGuy For what goes to you thread and the Hardwallets , I have to say that I like a lot of them (like 2. CryptoLabs "Case" looks pretty good) but they are just taking for ever , most of them are in development and don't wanna finish .
So I guess I will just stick to the free method for now then see my options when they all come out .

[gabridome]

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.

[Muhammed Zakir]

I suggest you to remember that 12 words seed. You can easily memorize it by creating a picture or story with it.

Brainwallet passphrase humans create which can be memorized very easily are relatively less secure. Brainwallets are hacked much and also like Shorena said, humans can't pick words randomly.

I suggest you to stick with Electrum or use Brainwallet with very random passphrase but I doubt it can be memorized easily.

[The Bad Guy]

After seeing all replies I decided to stick with Electrum afterwall
thanks for da help guyz , appreciate it was really useful