Not long ago on CoinSutra, we talked in detail about Bitcoin wallets in our article – Bitcoin Wallets: Everything A Beginner Needs To Know. Here I have told you about different types of Bitcoin wallets such as mobile wallets, cold wallets, web wallets, paper wallets, etc.
And these wallets are available for all cryptocurrencies, not just Bitcoin.
However, there is one more type of Bitcoin/cryptocurrency wallet called a brain wallet which I missed covering in my previous article.
What is a Brain Wallet?
Brain wallets, as apparent from their name, are a type of wallet where the user memorizes the mnemonic recovery phrase of their cryptocurrencies in their brain.
This mnemonic recovery phrase is used to derive the private keys of cryptocurrencies. It’s typically hard to remember or memorize private keys directly because they’re a long string of alphanumeric numbers.
A brain wallet is where a user remembers their mnemonic phrase/private key and never writes it down. And in some cases, if the user forgets the mnemonic phrase or dies without telling anyone or goes into a coma, then the associated bitcoins or crypto-coins are lost forever.
How Does A Brain Wallet Work?
To explain the working of a brain wallet, I will again use the example of Bitcoin for simplicity.
Typically, any Bitcoin brain wallet generator allows its users to key in random words (i.e. 4,6,8,12, or 24 words long) which is called a passphrase. This passphrase, depending upon the type of generator you are using, is hashed with SHA-256 or the Scrypt algorithm to generate a Bitcoin private key and then a Bitcoin public key.
The hash of these passphrases is computationally impossible to reverse. That’s why if you have chosen a hard to guess passphrase, it will be impossible for an attacker to steal your funds. See our guide on “What is a Bitcoin Hash?“
So whenever you put a passphrase in the brain wallet generator, it will hash it using algorithms such as SHA-256 or Scrypt and provide you with a Bitcoin private key/Bitcoin public key pair.
Now, once you have the public/private addresses, you can store your funds on them anytime without worrying. This is because now your private keys will only be generated through the “brain wallet” (which is in your head).
How To Create A Bitcoin Brain Wallet?
To create a brain wallet, you only require a passphrase (i.e. a mnemonic phrase of 4, 6, 8, 12, or 24 words long).
And that’s why it goes without saying that the security of your funds is directly dependent upon the strength/complexity/difficulty of the passphrase you choose. Because if someone is able to guess your passphrase, you will lose all of your funds in an instant.
Hence, users are advised by all brain wallet generators to choose a passphrase which is hard to guess, even by brute-force attack techniques.
Typically, a brain wallet is chosen in 1 of 4 ways:
- You can choose and key in a random passphrase of 4,6,8,12, or 24 words long which you can remember or recall.
- You can use Bitcoin wallet software like Electrum, Armory, and Mycelium to generate a passphrase and memorize it.
- You can use a Bitcoin wallet software to generate a passphrase and add “salt” to it to make your final passphrase even more complicated and harder to guess
- You can use a text file, excel file, doc file, or an image file and add “salt” to it to generate a passphrase. In this case, you need to keep the original file extremely safe.
Out of this, the first method of putting in random words has proven to be vulnerable because human beings are predictable. Humans generally choose such sentences or words which are easy to guess or can be computed by highly sophisticated brute-force attack techniques. One such instance where a user had kept a passphrase that he thought was difficult lost 4 BTCs. See this Reddit thread for more details.
So to avoid such situations, some brain wallet generators suggest passphrases of sufficient entropy. And it is always advisable to use this in case you don’t have any complicated random set of words ready to be used as a passphrase.
Making your Bitcoin Brain Wallet from BitAddress
Making your Bitcoin Brain Wallet from brainwallet.io
How to secure your Brain Wallet?
#1. Don’t use passphrases or brain wallets generated by humans as they are predictable.
#2. Use Bitcoin wallet software like Electrum, Armory, and Mycelium to generate a passphrase and memorize it.
#3. Memorize the passphrase or mnemonic using the mnemonic pegging technique.
#4. Use a BIP32 generator for your brain wallet because it uses a slow hash which is much harder to crack.
#5. Use your hardware wallet’s (Trezor or Ledger Nano S) recovery seed or mnemonic as a brain wallet. You can do so by memorizing your 12 or 24-word long recovery phrase (or recovery seed) instead of recording it. This way you need not worry about changing your address, and simultaneously you can control many public addresses at once.
Advantages & Disadvantages of Brain Wallets
Using a brain wallet has its pros and cons…
|Only you know the mnemonic in your brain, so you just need to trust your memory.||If you suffer from any medical condition like amnesia or dementia, you will lose your coin keys with you.|
|There is no written record or possibility of an online hack.||As there is no written backup, if you forget your mnemonic phrase, then your funds are lost forever.|
|Your brain wallet is always safe from hacking.||If someone knows you have a lot of money in your paper wallet, they can steal that. But if someone gets to know that you have a lot of money in your brain wallet, you can get kidnapped.|
Brain Wallets For Different Popular Cryptocurrencies
Here are a few links for popular cryptocurrencies which allow you to generate a mnemonic for you to memorize and use a brain wallet.
|Cryptocurrencies||Brain Wallet Mnemonic Generators|
Disclaimer: You should use brain wallets at your own risk. It can be highly risky and dangerous because if you don’t use a sufficiently strong passphrase, you stand at risk of being attacked. Moreover, there are 365 x 24 x 7 programs running that are clubbing frequently used words, common names, and different combinations trying to figure out the passphrases.
Now it’s time to hear from you: What are your thoughts on brain wallets? Are you using a brain wallet? Let me hear your experiences in the comments below!
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