Blockchain technology has emerged as a revolutionary innovation in the field of information and cyber security, providing a decentralized, secure, and transparent method of recording and verifying transactions. At its core, blockchain is a distributed ledger technology (DLT) that enables data to be stored across a network of computers, ensuring that no single entity has control over the entire database. Each record, known as a block, contains transaction data, a timestamp, and a cryptographic hash of the previous block, forming a chain of blocks that is immutable and tamper-evident. This structure ensures that any attempt to alter a single block would require altering all subsequent blocks across the network, which is computationally infeasible, thus providing a high level of data integrity and trust. One of the key features of blockchain is decentralization, which eliminates the need for a central authority or intermediary to validate transactions. Instead, transactions are verified through consensus mechanisms such as Proof of Work (PoW), Proof of Stake (PoS), or more advanced protocols like Practical Byzantine Fault Tolerance (PBFT). In PoW, network participants known as miners solve complex mathematical puzzles to validate transactions and add them to the blockchain, receiving rewards in the form of cryptocurrency. PoS, on the other hand, selects validators based on the amount of cryptocurrency they hold and are willing to stake, reducing energy consumption compared to PoW. These consensus mechanisms ensure that all participants in the network agree on the current state of the ledger, preventing fraud and double-spending. Blockchain’s security is fundamentally anchored in cryptography. Each block’s data is encrypted using cryptographic algorithms, and the link between blocks is maintained through hash functions. A hash function converts data into a fixed-length string of characters, which is unique for each input. Even a small change in the block’s data produces a completely different hash, making any tampering instantly detectable. Additionally, digital signatures based on public-key cryptography are used to authenticate the identities of transaction participants, ensuring that only authorized entities can initiate or approve transactions. This combination of hashing, encryption, and digital