What is a private key? - Bitcoin Course

Updated: Sep 9, 2021

A private key is an alphanumeric, encrypted code that gives you access to your bitcoin or cryptocurrency funds. It is the only way to prove that you are the owner.

"Your own key, your own bitcoins, if you don't own your keys, you won't own your bitcoins" Andreas Antonopoulos

What is a private key's purpose?

A private key is only needed to verify that you hold a certain cryptocurrency address. When you own a private key, you have complete control over all transactions and expenditures on that address. A private key should never be shared with anybody or any entity; this is why it is termed a private key.

How does a private key appear?

A private key is a 256-bit number in Bitcoin and many other crypto-currencies, although this is not the format in which it is presented. The hexadecimal representation of a 256-bit integer is easier.

what is a bitcoin private key  scheme

An example of a private key is as follows:


*Under no circumstances should you use this private key*.

You had a private key that was linked to a public key and an address in the early days of Bitcoin. This was neither feasible nor secure. Since then, additional BIPs (Bitcoin improvement protocols) have been released to enhance the user experience. Wallets nowadays generate their own root seed, which takes on a different alphanumeric form.

It is possible to generate an endless number of private keys from this root seed. Because this is much too complicated to give a pleasant user experience, several modifications have been made from the beginning. Because a root seed is so long, a better approach is utilized, which is the mnemonic code, which helps us remember our root seed.

What is the definition of a mnemonic code?

A mnemonic is a system of patterns or phrases that aids memory recall of more complicated information. The statement "May I have a huge container of coffee beans" is an example of a mnemonic. This statement is a representation of Pi, with each letter matching to a decimal point of 3.14159265. Our root seed's mnemonic coding is a little more complicated, but the concept remains the same.

It's evident that a private key in root form is difficult to memorize. Most wallets provide a seed code of 24 words that represents your root seed in a much more straightforward manner. Mountain and bicycle are examples of frequent English terms.

These phrases will be revealed to you when you initially set up your wallet, and you should pay close attention to them. A decent preventative step is to write them down on a sheet of paper and divide them into two sections. Your keys are secure as long as you have access to both pieces of paper in case you lose your wallet.

How a bitcoin address is connected to a private key.