Lesson 2: What a key is — Baskin Logic Crypto Academy

A key here is not a house key. It is a secret number that proves a move is yours.

If you hold the key, you can sign. If someone else holds it, they can sign as you. Lose it, and the record does not come back.

That is the object. Not a product. Not a brand. The school does not tell you what to buy.

Key terms

Private key: A private key is a secret number that proves you own the crypto at an address and lets you sign payments from it.
Crypto wallet: A crypto wallet is a tool that holds the keys that control your crypto.
Seed phrase: A seed phrase is a list of 12 to 24 ordinary words that can rebuild your crypto wallet.
Not your keys, not your coins: "Not your keys, not your coins" is a crypto saying.

Five questions from this lesson. Your score stays on this device.

Show the answers

A secret number that proves a move is yours. A key is a secret number. It proves a move is yours.
Sign a move. Holding the key lets you sign, which means approving a move.
Sign as you. Anyone who holds your key can sign as you.
No, never. No real helper needs your private key. Anyone asking for it is a warning sign.
No one, unless you have your own backup. Lose the key and the record doesn't come back. Your backup, the seed phrase, is covered in Lesson 3.

Written and reviewed by Joshua Baskin, founder. Last reviewed October 2, 2026. How we check facts · Report an error

This lesson explains a basic idea and does not quote outside figures. Terms follow our glossary, and rule pages link to the official text.