In cryptography, a public key is one-half of a key pair used in a system called public-key cryptography (PKC). Every public key has a related private key. It's easier to understand if we imagine a lock and key system. You can think of the public key as a lock and the private key as the unique key that opens the lock. This system enables secure communication and data exchange between parties who may not necessarily know each other.
In the crypto world, a public key functions as your cryptocurrency wallet's address. Just as you have a physical address where friends can send you letters, your public key is like a digital address where others can send you cryptocurrencies. It's a unique alphanumeric code that helps identify your wallet on the blockchain. You can think of it as a mailbox number in a vast digital neighborhood.
Every public key has a related private key. In fact, public keys are generated from their respective private keys.
While the public key can be shared openly with others, the private key should be kept confidential. Imagine the public key as your home address, which you can share with friends, and the private key as the magical key that opens the door to your home – your cryptocurrency funds.
The generation of these keys starts with the creation of the private key. It works like a secret code that's mathematically linked to your public key but cannot be derived from it. Once the private key is in place, the public key is generated from it using a complex algorithm. The public key can then be shared with the world. It's safe to share because even if someone knows your public key, they can't reverse-engineer it to find your private key.
Now, let's talk about how the public key comes into play during cryptocurrency transactions. When you want to receive funds, you share your public key (your digital wallet address) with the sender. They use this address to send you cryptocurrencies, just like sending a letter to your mailbox.
But how do others know you're the rightful owner of the funds sent to your public key? This is where the magic of the private key comes in. When you want to access or spend the funds received, your wallet uses the private key to sign the transaction. This digital signature proves that you're the legitimate owner of the funds associated with your public key.
As we’ve learned, the public key can be openly shared, but the private key is a treasure that must be protected at all costs. Sharing your private key is like giving away your funds – whoever possesses it gains control over your cryptocurrency.