Open and Private Keys in the World of Cryptography

It is important for all aspiring cryptographers to understand what public and private keys are and what they do. The following is a brief guide.

Public and private keys in the cryptocurrency world: what are they?

The first thing you need to do when entering the cryptocurrency world is to open your wallet. It is at this point that you begin to deal with public and private keys. But what are these?
A public key is a cryptographic code that is used in tandem with a private key to receive cryptocurrency transactions. While anyone can send transactions to a public key, you need the private key to "unlock" them and prove that you own the cryptocurrency resulting from the transaction.
The public key that can accept transactions is usually a wallet address, which is a 42-character string provided by the recipient to receive the cryptocurrency. A wallet address is simply an abbreviated form of a public key that functions as the IBAN for a particular cryptocurrency account.
In general, people can share their public keys freely and without fear. In contrast, a private key is for the owner of the wallet only and must be kept secret.
In fact, in the cryptocurrency world, a private key acts as a password to access one's cryptocurrency wallet. If this password is accidentally lost or stolen, anyone with it can access the wallet and do whatever they want with the found cryptocurrency.
Specifically, private keys are numeric codes that can take many forms, such as a 256-character binary code, a 64-bit hex code, a QR code, or even mnemonics.

Public and private keys in various cryptocurrencies

Speaking of private keys, it's important to know how the cryptocurrency wallet you decide to use to store your cryptocurrency works.
In fact, many cryptocurrency wallet providers encrypt private keys in a way that makes them easier to record and remember.
Some wallets use an "initial phrase," also known as a "secret recovery phrase," to unlock the wallet. If a non-castodial cryptocurrency wallet from MetaMask is selected, the user is given a string of random words to unlock the funds. The private key is hidden in the software behind this string of user-friendly words.
Otherwise, if the wallet of choice is a centralized platform such as Binance or Coinbase, the company will store the private key on behalf of the user. In this sense, the wallet provider controls the funds on behalf of the user.

Public and private keys and digital signatures for cryptocurrency transactions

Public and private keys are primarily used to sign cryptocurrency transactions. The function of this digital signature is to authenticate the transaction on the corresponding blockchain.
The steps for transactions on a blockchain are listed below:
 The transaction is encrypted using a public key. The transaction can only be decrypted with the accompanying private key;
 The transaction is then signed using the private key to prove that the transaction has not been altered. The digital signature is generated by linking the private key to the data sent in the transaction;
 The use of the accompanying public key allows the authenticity of the transaction to be verified.
The user digitally signs the transaction to prove that he/she is the owner of the funds. The host automatically verifies and verifies the transaction. Any unauthenticated transaction is rejected by the network. Transactions that have been authenticated and mined on the blockchain are irreversible.