What is a seed phrase?
In the early days of Bitcoin, a wallet only generated one private key, which meant there was also only one public key and one address.
Nowadays, crypto wallets now give you the ability to generate an almost unlimited number of private keys from a “master private key“.
This type of wallet is known as a “Hierarchical Deterministic wallet”, or simply as an “HD wallet”.
It first generates a master private key, and then the wallet software uses this to create “child” private keys and their corresponding public keys, which then form addresses.Think of the master private key as a (single) “parent” private key that can create lots of “child” private keys. This creates a sort of tree structure where “child” keys are derived from a “parent” key.
As you can see from the image above, the master private key is generated from a “seed phrase“.
The wallet uses this seed phase to create private keys.
Because all the “child” private and public keys are ultimately derived from the master private key, they can all be controlled by the same seed phrase.
What is a Seed Phrase?
When you first set up a Bitcoin wallet, you will be shown a series of 12 to 24 seemingly random words.
Not only are the words themselves are important but the order of the words is equally as important.
This series of words listed in a specific order is the wallet’s “seed phrase“.
Here’s an example of what a seed phrase looks like:
Depending on the wallet, a seed phrase may go by other names like:
- recovery phrase
- mnemonic phrase
- secret phrase
- mnemonic seed
- mnemonic seed phrase
- seed key
- wallet seed
- secret recovery phrase
Or some combination of the words:: “seed”,”wallet”,”recovery”, “mnemonic” or “phrase”.
All of these names ultimately mean the same thing and simply describe the 12 or 24 words that comprise the seed phrase.
Words are chosen from a defined list of 2048 words, and any combination of words is a valid seed phrase.
The reason that the seed phrase is a series of words such as “acid,” “else,” “farm,” “gym,” “opera,” “soda,” “trash,” or “view”) rather than a numeric password is because long numbers are difficult for humans to read and remember.
Behind the scenes, this series of words, entered in the right order, is converted by the wallet software into a string of digits.
This string of digits is known as the “seed“.
And it is this “seed” or string of digits that generates the master private key!
And this master private key is what’s used to generate “child” private keys, as well as their public keys, allowing a wallet to generate as many key pairs as needed.
The cool thing is you never have to know about the seed! It’s too damn long. That’s why the wallet software creates a “seed phrase” (or “mnemonic phrase“) to represent the “seed“. It’s a much simpler format and easier to remember.
The important thing to know is that ALL your private keys are generated from and tied to the seed phrase.
Write down your seed phrase and store it in a safe place!
When your wallet software generates a seed phrase, it will usually instruct you to write it down on paper.
Write down your seed phrase and store it in a safe place.
If you want even more security, write it down on multiple pieces of paper and store each in different locations.
Since all keys in the HD wallet are derived from the seed phrase, this makes it possible to re-create the entire HD wallet from that seed in any compatible HD wallet.
As long as you have your wallet’s seed phrase, you’ll have access to all of the bitcoins associated with the wallet that generated the phrase…even if something unfortunate happens to your wallet.If your computer breaks, you can download the same wallet software again and restore your wallet and recover your funds by providing your seed phrase.
Different wallets will have different instructions for recovering a wallet but in general, you’ll be asked to type or choose words in the specific order of your seed phrase to restore your wallet.
Never take a screenshot of your seed phrase and never save it on a digital medium like a Word/Google doc, email, or text message. If your computer or phone gets hacked, say goodbye to your bitcoins!
Make sure to keep your seed phrase private. Don’t share it with others! Try not to even mention you have a seed phrase. Anyone with your seed phrase will have access to your wallet and all of its funds.
If someone asks for your seed phrase they are likely trying to scam you and steal your wallet funds.
What happens if you lose your seed phrase?
Think of your seed phrase as a special kind of password. It is the ONLY way to access your wallet.
In the event that your wallet gets lost, deleted, corrupted, broken, or destroyed, your seed phrase is the one thing that can restore and recover your wallet.
If you delete or lose your wallet WITHOUT saving your seed phrase, your bitcoins are gone.So hopefully, you didn’t accidentally throw away that slip of paper where you wrote your seed phrase on.
Unless someone steals your seed phrase, your bitcoins will remain safely stored on the blockchain, but you won’t have any way to access it
Without your seed phrase, you lose access to your crypto forever. So remember to keep your seed phrase safe!
Is it possible for someone to guess your seed phrase?
A seed phrase comes from a specific list of 2,048 words. This would require someone to be able to guess all the words from that huge list of words AND put them in the correct order.
For example, for a 12-word seed phrase, there are 777,788,267,247,859,345,059,141,959,844,041,626,185 possible combinations.
The likelihood of someone guessing your seed phrase is basically zero.
What’s the difference between a seed phrase and a private key?
When you first create your wallet, it generates a seed phrase.
The seed phrase generates a master private key.
And this master private key can create an almost unlimited amount of private keys.
If you think of each private key as a “password” that allows you to send or spend bitcoin tied to a specific address, then the seed phrase acts as a “master password“.
As long as you know the “master password” (seed phrase), then you have access to ALL private keys in the wallet.
If it weren’t for the seed phrase, you would have to keep track of your private key for each and every address that you own! Dealing with multiple addresses (and their private keys) would be a pain in the butt.
Thankfully, the wallet removes the need for you to worry about your private keys (and public keys) and can manage all your funds using just the seed phrase.
Wallets deal with all of the creating and managing of keys in the background. All you need to know is the seed phrase!
If you’re familiar with password managers (like LastPass, 1Password, or Bitwarden), you can think of a wallet as like a crypto password manager and a seed phase being similar to the master password.
Summary
- Public and private keys are always created in pairs.
- The public key is used to RECEIVE bitcoins.
- Due to its length, it is compressed into a format known as the address
- The address is similar to an account number of a bank account.
- The private key is what authorizes you to control funds attached to an address and initiate transactions from that address.
- A seed phrase is a human-readable master private key in the form of a sequence of words. It can contain an unlimited amount of public/private key pairs.
- If a seed phrase is lost, there is no way to retrieve it.
As you can see, “storing” bitcoins in an HD wallet simply refers to the safekeeping of a seed phrase.