Blockchain Technology for Beginners

Explore the core components of blockchain, including nodes, transactions, blocks, miners, and the consensus protocol, and how they sustain a distributed ledger.

Learn hashing by converting data into fixed-length hash values with hash functions, SHA-256 in blockchain, and observe that changing data changes the hash while identical data yields the same hash.

Showcases the structure of blockchain as an interlinked chain of blocks, each block containing block number, nonce, data, previous hash, and hash, secured by proof of work and tampering detection.

Discover how tampering is detected in a blockchain's distributed network by comparing block hashes across nodes; tampering alters hashes and propagates errors to subsequent blocks, exposing inconsistencies.

Explore the key elements of blockchain technology, including distributed ledger technology with many nodes, peer-to-peer decentralization, immutability through cryptography, and provenance of transactions.

Explore centralized, decentralized, and distributed networks, where a single authority, no authority, or interconnected nodes shape transaction outcomes; blockchain is a decentralized, distributed ledger with no central control.

Discover how peer-to-peer networks connect computers with equal permissions and responsibilities for processing data, without designated servers, a system on which blockchain operates.

Blockchain is a form of distributed ledger with immutable records, where every blockchain is a database, but not every database is blockchain, as data sits in blocks.

Explore the three types of blockchain—public, private, and consortium—and learn how open participation, permissioned access, and multi-organization governance shape a peer-to-peer distributed ledger.

Explore the differences between public, private, and consortium blockchains by examining who can join, read permissions, tampering risk, centralization, and permissioned versus permissionless consensus.

Build a simple blockchain application with Django to explore block mining, proof of work, validation of the chain, and interlinking of blocks using Python.

Set up python, activate a virtual environment, install django, and start a blockchain project with a blockchain app. Run the server and define routes for mine and chain requests.

Define a blockchain class with block, chain, and validity checks, import modules, and instantiate it on server start to handle requests.

Define functions for each GDP request type and interact with a blockchain object to verify operation, then start the server and test endpoints in a browser.

Define the blockchain class in Python by implementing the __init__ method, initializing a gene list of blocks as dictionaries, and creating the first block with a create_block method.

Create a create_block method to form blockchain blocks with index, timestamp, nonce, and previous hash, then append to the chain, starting with a genesis block.

Create and implement the get_last_block method to retrieve the last block of the blockchain using indexing, returning the final element of the chain.

Explore proof of work by iterating nonces, hashing with a 256-bit algorithm, and checking for four leading zeros to yield a valid block nonce.

Hash the current block by converting the block dictionary to json, hashing with the hash library, sorting keys alphabetically, and converting the result to hexadecimal.

Apply the is_chain_valid method to verify the blockchain by iterating blocks, ensuring each current block’s previous hash matches the prior block, and confirming proof of work with four leading zeros.

Learn to fetch the blockchain with the get_chain function and mine new blocks, validate the chain, and view json responses in a simple server setup.

Explore how the mine_block URL function uses previous blocks, a nonce, and the previous hash through a proof-of-work approach to create a new block.

Create the is_chain_valid function to verify the blockchain's integrity using a boolean is_valid and read blockchain data, returning 'blockchain is invalid' or 'problem with the chain' based on validity.

Learn how to detect tampering in a blockchain by changing the nonce and validating the chain, then observe how tampering makes the blockchain invalid.