Seed phrases and private keys
What a seed phrase is, how to back it up safely and why you must never share it.
A private key is a secret number that lets you sign transactions and move funds from your address. Modern wallets generate your keys from a seed phrase (also called a recovery phrase) — usually 12 or 24 ordinary words in a specific order.
Why it matters
Whoever knows your seed phrase controls your wallet. They can restore it on any device and move your funds. There is no "forgot password" button on a blockchain.
How to back it up
- Write the words down on paper (or engrave them on metal) in the exact order.
- Keep the backup in a safe place, away from damp, fire and other people.
- Consider keeping a second copy in another safe location.
- Check that you wrote it correctly before you send funds to the wallet.
What not to do
- Do not take a photo or a screenshot of the phrase.
- Do not store it in notes apps, email, cloud drives or messengers.
- Do not type it into websites or forms.
- Do not share it with anyone — including "support staff".
Passwords are different
A password protects an account on a service (such as your XFasil account). It can be reset through your email. A seed phrase protects a self-custody wallet and cannot be reset. Treat both seriously, and protect your email account, because it is often the key to resetting other passwords.
University materials are for education only and are not investment, legal or tax advice.