Brainwallet, found online at Brainwallet.io, generates deterministic bitcoin addresses for you. Find out how it works today in our review.
What is Brainwallet?
Brainwallet is a deterministic bitcoin address generator. The website lets you generate an address, then store bitcoin “in your brain” by remembering your passphrase and salts. All password generation takes place in your browser, and Brainwallet claims that no information is ever sent to their server (you can also run the website offline).
In other words, Brainwallet lets you create a secure passphrase for your Bitcoin. As long as you remember that passphrase, you have access to your bitcoin. You can write that passphrase down or store it in your brain.
Brainwallet recommends using a long, unique passphrase that has never been used in any song, book, movie, TV show, whatever. If you use a weak passphrase, then you’re at risk of having your bitcoin stolen.
Brainwallet recommends a minimum of 8 random words. Most people, however, will choose to randomly generate a secure 12 word passphrase – similar to the 12 word passphrase generated by most bitcoin wallet apps or software.
Meanwhile, your “salts” are used as additional inputs to the cryptographic function that generates your Brainwallet. This information never gets sent to the Brainwallet server, and it’s only used to strengthen your passphrase. You’ll need to enter at least one salt, and you can choose between different types of salts.
With Brainwallet, there’s no recovery process – so don’t forget what you enter. Write your passphrase and salts down, memorize them, or secure them in some other way.
How to Recover Funds with Brainwallet
Recovering funds with Brainwallet is as easy as entering your passphrase (the 8 or 12 words) and your salts. That’s it. You’ve successfully restored your bitcoin from your “brain”.
Instead of entering a passphrase, you can drop any file into the text box and your browser will perform an SHA256 hash on the file to derive a checksum. This checksum is used as your passphrase.
All file hashing takes place in your browser, and it never gets sent to or stored on the server. For this process, Brainwallet recommends using a file that has never existed on the internet, and to keep that file stored securely. Many people choose to use a unique photograph that they have personally taken.
How Does BrainWallet Work?
Brainwallet uses the scrypt key derivation function to generate bitcoin addresses. Salt inputs are concatenated (yes, that’s a real word) and used as the salt for the scrypt function.
Here’s the process in pseudocode:
- key = scrypt(passphrase, salt, N=218, r=8, p=1, dkLen=32)
- keypair = generate_bitcoin_keypair(sha256(key))
Scrypt is a memory-intensive function. Brainwallet deliberately chose this function because of its defense against brute force attacks. Performance can vary depending on your hardware. On some systems, it might not work at all. If you encounter problems with Brainwallet, the developers recommend using a newer computer or a different web browser. As their website explains, “We can’t sacrifice security for legacy support.”
Brainwallet can also be run offline. It’s a self-contained website. You just need to download the latest HTML file from Github, verify file integrity (checksum) with the PGP-signed changelog, then run it on an air-gapped computer. Keep a copy of the HTML file that you used to generate your Brainwallet for safekeeping.
Who’s Behind Brainwallet?
Brainwallet was created by a man named Daniel Routman. Daniel has posted his donation link on the Brainwallet.io website. Brainwallet.io is licensed under the MIT License (MIT). It appeared online in 2015.
Brainwallet is a fast, easy, and effective way to create a “brain wallet” for your bitcoin. You can use the website online or offline to generate a passphrase and salts for your bitcoin keys. As long as you remember the passphrase and your salts, you’ll be able to recover your bitcoin. It’s like storing your bitcoin in your brain.
To start using Brainwallet, visit online today at Brainwallet.io.