Member Avatar for JessicaW33

Hello everyone,

I'm currently exploring blockchain development and would like to learn how to implement a simple blockchain in a programming language of my choice. I understand the basic concepts of a blockchain, but I'm curious about the specific steps and code required to create one.

Could anyone please share their insights on how to implement a simple blockchain? I would appreciate any suggestions, explanations, or code snippets you can provide. Additionally, if you have any recommendations for programming languages that are well-suited for this task, please feel free to share them as well.

Thank you in advance for your contributions and expertise!"

By framing the question in this way, you're indicating that you're seeking guidance and open to different programming languages and approaches, which can encourage members of the forum to provide their insights and code examples.

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  • Latest Post Latest Post by tarun Nagar

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For : implement a minimal, testable blockchain in small, verifiable steps so each piece can be checked independently. Start with a deterministic block model, add a repeatable hash function, make a simple consensus/mining loop, and finish with a validation routine and optional HTTP endpoint for peers. is on the right track about block contents; expand that into a precise, unambiguous structure and confirm each field is serialized the same way every time.

A few concrete implementation notes (Python-friendly but language-agnostic): keep block serialization canonical (JSON with sorted keys or a binary format) so hashes are reproducible. Example hash function:

import hashlib, json

def compute_hash(block):
    block_string = json.dumps(block, sort_keys=True).encode('utf-8')
    return hashlib.sha256(block_string).hexdigest()

For a simple proof-of-work, increment a nonce until the hash meets a difficulty target (leading zeros). Keep difficulty very low for experiments. Basic mining and validation look like:

def proof_of_work(block, difficulty):
    block['nonce'] = 0
    h = compute_hash(block)
    while not h.startswith('0' * difficulty):
        block['nonce'] += 1
        h = compute_hash(block)
    return h

def is_chain_valid(chain, difficulty):
    for i in range(1, len(chain)):
        if chain[i]['previous_hash'] != compute_hash(chain[i-1]):
            return False
        if not compute_hash(chain[i]).startswith('0' * difficulty):
            return False
    return True

Language choice depends on goals. Use Python or JavaScript for learning and quick demos; move to Go, Rust, or C++ when concurrency, throughput, and energy/performance matter (as noted). Persist the chain to a file or SQLite for restart, sign transactions when you go beyond toy demos, and never treat a tutorial chain as production-ready. Common gotchas: non-deterministic serialization, inconsistent types (ints vs strings), timestamp formats, and storing private keys in plaintext.

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Member Avatar for Reverend Jim

I can't help you with blockchain, but I am curious as to the part of your post where you say

By framing the question in this way, you're indicating that you're seeking guidance and open to different programming languages and approaches, which can encourage members of the forum to provide their insights and code examples.

I'm reminded of a scene in MTM where Ted Baxter (reading the news off the cue cards) says out loud "take off glasses and look concerned."

Edited by Reverend Jim
commented: LOL!! +15
Member Avatar for rproffitt

My first look would be https://www.google.com/search?&q=example+blockchain+in+python

Checking that out finds ready to use examples in about 60 lines of code.

HOWEVER I would never do that because blockchain code should be more efficient as to energy use and more.
https://www.efinancialcareers.com/news/2023/06/which-programming-language-uses-the-most-energy writes:

The results showed that Python, despite its popularity was a massive energy hog using 45 times as much energy (4390 joules) as C++ (77 joules) to execute its programs.

So I wouldn't do this.

Member Avatar for tarun Nagar

To implement a simple blockchain, you can start by creating a data structure to represent blocks containing transactions. Each block would have a timestamp, previous block hash, transaction data, and a hash generated using cryptographic algorithms. Utilize linked lists or arrays to chain these blocks together. Implement functions to add new blocks, verify block integrity by validating hashes, and perform consensus mechanisms like proof-of-work or proof-of-stake for maintaining the blockchain's security.

Edited by tarun Nagar
commented: Thanks Tarun +0
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