A brainwallet is a type of cryptocurrency wallet in which the seed phrase of the same is created by ourselves in order to facilitate the support of said wallet, this instead of using an algorithm as is normally done in other types of wallets .
Una brainwallet or brain purse, is a type of cryptocurrency wallet in which the safety of the words used for the generation of the seed phrase From the purse, it sits on a series of words or phrases that a person can easily remember. Basically You can think of a brainwallet as a wallet where the seed phrase of your private key can be memorized. Thus, it is stored in your brain, and in case you need to access it, you will only have to remember this information and thus obtain control of your coins.
In this point, a brainwallet is just a modification of the HD wallets who use the standards BIP-39 y BIP-47 for its funtionability. Only in a brainwallet, The generation of the seed phrases does not fall into an algorithm that makes sure to build a unique entropy for your wallet, but you choose the entropy to use.
The concept may seem great to you, the idea of using a phrase or words easily recognizable by you to save your cryptocurrencies, instead of difficult English words, is simply much better. However, there is a serious problem with this system: If you are not able to create truly unique, unrepeatable and complex keys, you could lose your cryptocurrencies without being able to do anything to remedy it.
You may wonder why this scenario is possible? How does a brainwallet really work? Well, we will examine that next.
How does a brainwallet work (and is it generated)?
The operation of a brainwallet as we explained at the beginning, does not differ from that used by the standard HD wallets that we use today. Normally when you use a cryptocurrency wallet on your smartphone or hardware wallet, you go through a generation process, in which, at a given point, you are asked to write down a series of 12, 18 or 24 words. These words (generally in the English language) are the well-known seed phrases (mnemonic phrases) and are the preamble to the construction of the master private and public keys of your wallet.
The seed phrase can be seen as a unique and unrepeatable representation of the "entropy" that will be used to build the private and public keys of your wallet. A representation that will help you easily back up your wallet. It may seem complex to have to write down these words to back up your wallet, and even more to find a safe place and memorize them, but it is much better to have those words than to write down a pure ECDSA private key.
To give you an idea, a seed would have this form:
loyal essay fancy exile tomorrow solid pumpkin define enter gadget diary stumble
Whereas an ECDSA private key, it would have this form:
5JRw8gB56aWf24ThCY71YK9eoxu7MwiN4uVrt178YKZa2hLWkFq
The difference is enormous, and the seed is certainly easier. But what if we change all those words for something simpler? Well, you can and that is the brainwallet. The process is the same, you enter the words or phrases that you will use as entropy, the wallet takes this information and transforms it into your private and public keys for your wallet.
To prove our point, we will use this generator of brainwallet in order for you to see the process.
If we access the generator and use this phrase (of 18 words) as a seed, we will see the following:
creating my own brainwallet purse to keep my cryptocurrencies totally safe at all times, places and circumstances
Quickly, it shows us the result:
And no matter where you are and when you do it, the result is the same. This is because the same derivation mechanism used in BIP-39 and BIP-47 is used, being an entirely deterministic process. That is, if you enter the same seed over and over again, the result will be the same, regardless of the time, place, or operating system you use to generate the wallet. Go ahead, test at home, and you will see that the private key of the seed described above is the following:
5Jp6SHCAGrpzi65UUARCDPTsVYYLbH8G8j982aVHhK9j6Ae5cry
This way you will have complete certainty that the process works as explained, and at the same time, you will have the assurance that, if we enter the same phrase, we will always obtain the same private and public keys for our wallet.
However, the problem with this is that that phrase can be thought by anyone else, and if that scenario occurs, access to the cryptocurrencies stored in that wallet would be in the hands of another person, and losing them would be very simple.
How much do you know, cryptonuta?
Does the security of a brainwallet depend on it being created in an offline environment?FALSE!
The security of a brainwallet depends mainly on the phrase that we choose to form the "seed" of our wallet, with its offline creation being just an additional security measure that is welcome in this case. Remember, that to have a secure brainwallet you must choose unique phrases, not easily identifiable, but not even with this measure, the good security of a brainwallet is guaranteed.
Security, the weak point of brainwallets
Security and lack of entropy is what makes brainwallets weak. You could think at the time of creating your wallet, in a phrase that you consider unique, but in this world of more than 7 billion people, it may be the case that you are not the only one who has thought of the same thing, with the same words , and try it with a purse. Probably that is rare, but highly possible.
The problem increases even more by our own nature, we are beings with great memory capacities, but if we do not use that word or phrase repeatedly, we will most likely forget it. Faced with this fact, what usually happens is that we use the same patterns to secure things of value, which leaves us at the mercy of any social engineering attack, and that would lead the hacker to steal our keys. Do you see it unlikely? Well, tell the millions of people around the world who use the letters "qwerty" "dvorak", "1234567890" or their DNI number as their email password. Cases like that are not uncommon in the computing world, and if we bring it to the crypto world with brainwallets we will see the same pattern.
It is not uncommon to think that someone comes and uses a Psalm (yes, the biblical ones) for the seed of their purse, or the phrase of a famous actor or song, they are simple ways to remember things that are important to us and help us protect values in certain scenarios, but in crypto, this is dangerous. In fact, it is enough to put a small GPU farm to attack this type of wallet and succeed, and the result of this would be that of large numbers of people who would not understand how their bitcoins have disappeared from the wallet, believing that Bitcoin has a problem, when it has nothing to do with Bitcoin.
Hence, cryptocurrency developers always aim to use seed phrases as designed, because they provide a great entropy in each case and, therefore, no wallet will be the same as another, and only by backing up your seed, you can recover access to your coins quickly.
Given this scenario, our highest recommendation from Bit2Me is: AVOID using brainwallet wallets to keep your cryptocurrencies safe. Instead of finding a safe place for your holdings, what you are doing is creating a weak and cryptographically insecure space, which others with some work can break.