Keys and blocksCryptography is the technique used to protect privacy of a message by transforming it into a form that can be understood only by the intended recipients. Everyone else will see it as only an unintelligible sequence of random characters. This message manipulation is enabled by a pair of keys, public and private keys: You share your public key with your friend, who uses it to transform his message to you into an unintelligible sequence of random characters. You then use your private key to put it back into its original form.The special mathematical properties of these two crypto keys are widely used to provide secrecy and integrity. Two crypto keys play the role of digital signatures and are commonly used in blockchain to enable both authentication and anonymity for transactions.Blockchain is a crucial technology for creating NFTs. It uses cryptography to chain blocks into a growing list of records. Each block is locked by a cryptographic hash, or string of characters that uniquely identifies a set of data, to the previous block. The transaction records of a chain of blocks are stored in a data structure called a Merkle tree. This allows for fast retrieval of past records.To be a party in blockchain-based transactions, each user needs to create a pair of keys: a public key and a private key. This design makes it very difficult to alter transaction data stored in blockchain.
