Gamified Flashcards on Blockchain Technology PDF

Gamified Flashcards on Blockchain Technology What is Blockchain A blockchain is a distributed ledger that maintains a continuously growing list of ordered (sequenced) records called “blocks.” The blocks are linked together and the integrity of data records is secured using cryptogra...

Gamified Flashcards on Blockchain Technology What is Blockchain A blockchain is a distributed ledger that maintains a continuously growing list of ordered (sequenced) records called “blocks.” The blocks are linked together and the integrity of data records is secured using cryptography. Specifically, the growing lists of records (blocks) use cryptographic “hashes” to link in sequence. Each block contains 1. a cryptographic hash of the previous block, 2. a timestamp, and 3. transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a chain of record blocks, with each additional block linking to the ones before. Blockchain transactions are irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks. This is achieved because of the features of cryptographic hashes. You will learn more about these and Merkle trees later. 2. Basic Structure of a Blockchain Blockchain Blocks, Transactions and the Chain When building your mental model on blockchains, it is useful to understand what blocks and transactions are, and how the two of those combine to form a blockchain. Blocks A block is similar to a digital container. This container holds a list of transactions, a timestamp, and a unique identifier called a cryptographic hash. Each block also contains the previous block’s hash, effectively “chaining” them together by their unique identifiers pointing to the previous blocks unique identifier. This linkage ensures the integrity and continuity of the blockchain. For now, remember that a block contains: Transaction data Timestamp Hash of the previous block Nonce Some of these technical terms are explained in more detail in later chapters. Transactions In blockchain terminology, a transaction is a bundle of information that gets stored permanently on a blockchain. Transactions on blockchains are used for: Transfer of value (eg assets like cryptocurrency) storage or updates to data on the blockchain: ○ A message from one address to another  ○ A smart contract deployment ○ An interaction with a smart contract that changes the data stored on the blockchain The Chain Blocks are linked together in chronological order, forming a chain. The cryptographic hash of the previous block in each block ensures the integrity and immutability of the blockchain. This structure ensures that transactions become a permanent part of the blockchain.