In the previous chapter, we explained that an address is linked to a "private key" and a "public key," which are necessary when actually executing a transaction.

Cryptocurrencies employ a method called public-key cryptography, where the "address," "private key," and "public key" are always a set.
That is
"Create private key ⇒ Create public key ⇒ Create address"
This is because it is created in the following way.

This process is irreversible, and it is impossible to identify the underlying private or public key from the address.
Of course, it's also impossible to determine the private key from the public key.

Now, let's take a look at how it's actually used in transactions!

For example, if Alice wants to send 1 BTC to Bob, it would look like this.
① Alice creates a transaction to send 1 BTC from Alice's address to Bob's address.
② Alice encrypts the created transaction by signing it with her private key and then publishes it on the network.
③ Miners use Alice's publicly available public key to verify whether this transaction was actually made by Alice. (This is mining!)
④ Verification results show that the "transaction before encryption" and the "decrypted transaction" match, proving that Alice sent this transaction.
⑤ The money will be sent to Bob's address. Transfer complete!

It's easier to understand if you think of the address as your bank account number and the private key as your bank account's PIN.
Incidentally, a public key is used to generate account numbers and to verify that a transaction is legitimate.

- Your address (account number) is necessary if you want someone to transfer money to you; you must share this information with the person you want to receive the money from.
If your private key (PIN) is revealed to someone else, they will be able to withdraw money freely, so it would be a serious problem if it were leaked to others.
• Public keys are used to verify the legitimacy of transactions, so transactions cannot be conducted unless they are made public.

Store your private key securely so that no one else can find it!