What is a Bitcoin Seed Phrase?
An example of how a seed phrase will look written down
Hi Plebs,
A Bitcoin seed phrase, also known as a seed backup, recovery phrase, mnemonic phrase, is a human readable representation of a seed - which is a long random string of digits. The seed phrase consists of 12 or 24 words and is used to derive the keys that allow you to spend your Bitcoin funds.
When you create a new Bitcoin wallet , whether a software or a hardware wallet, it will generate a fresh seed phrase for you. You are then instructed to write down this seed phrase securely as it acts as a back up to recover your wallet and regain access to your funds if needed.
How Bitcoin Seed Phrases Work
Technically, the 12 or 24 word seed phrase is generated from a master seed, which is that long random string of digits. This master seed is used to mathematically extract the master key for your wallet. From the master private key, all other private keys controlled by the wallet are acquired. Those private keys then allow you to generate public key addresses to send and receive bitcoin.
Possessing the seed phrase allows you to recreate and control the entire hierarchy of keys for that bitcoin wallet. This makes the seed phrase critically important to backup and keep secure, as it represents complete control and access to any bitcoin stored in that wallet.
The words that make up the seed are drawn from a list of 2048 predefined words specified in the BIP39 bitcoin standard. This allows for an incredibly large combination of possible phrases, making them extremely difficult to guess.
Because wallets following BIP39 interoperability standards generate the seed phrase from the same 2048 word list, a seed phrase backed up from one brand of hardware wallet can be used to recover funds in a wallet from a different manufacturer if needed.
Here’s a useful video that explains BIP39
A seed phrase stamp onto metal for extra durability, compared to a phrase written on paper
Securing Your Seed Phrase
All leading wallet manufacturers strongly recommend writing down your seed phrase during wallet set up and storing it safely. For substantial bitcoin holdings, best practices include using metal backups (where the phrase is stamped onto the metal), safety deposit boxes, or geographically distributed backups in multisig.
If your seed phrase is ever compromised or lost, you’ll need to transfer any bitcoin it controlled to a new wallet and seed phrase that you control the backup for. With proper precautions, your seed ensures you can always retain self-custody of your bitcoin, even if you lose a physical wallet device.
Cheers, and onwards with Bitcoin
