Questions tagged [blockchain]

A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography. Each block typically contains a hash pointer as a link to a previous block, a timestamp and transaction data. By design, blockchains are inherently resistant to modification of the data. A blockchain can serve as an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.

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Deposit and Point accrual contract

I've created a smart contract in Solidity and would like to ask for some review to highlight any potential issues. The primary goals of this contract of this contract are to: Allow users to deposit ...
HudsonGraeme's user avatar
3 votes
1 answer

Bitcoin Hash (Merkle) Tree implementation in Java

I'm learning about how full nodes can send a Merkle root + a list of hashes, so that a light client can verify a transaction. I couldn't find any good resources on how to implement it. I just knew ...
user644361's user avatar
3 votes
1 answer

Grokking the basics of BlockChain with Python

As I was streaming I had a brilliant visitor suggest we write a blockchain in Python. So we did. Note that there is no validation or voting simulated here. Here's the results, in ...
Aaron Hall's user avatar
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2 votes
1 answer

A register of government decrees, authenticated with blockchain and public key cryptography

The full repo is here, but I'll post the most important extracts below. Background I'm trying to get the hang of blockchain and public key cryptography, so I thought it would be fun to create a ...
Tom Hosker's user avatar
1 vote
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Solidity: verifying primality certificates, bounty for large primes

This is my first smart contract, and it isn't finished yet, but the remaining bits are complicated enough that I'd like to make sure I'm on the right track first. My concerns are: At line 117, is the ...
Pr0methean's user avatar
2 votes
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Bash bitcoin blockchain explorer

I wrote a little bash script that displays the transaction info in json: ...
reardenlife's user avatar
6 votes
1 answer

Blockchain implementation in F#: Block and Blockchain

Some time ago I started writing a blockchain implementation for learning purposes. I used this article as reference. Originally I wrote the code in C# but recently I have rewritten everything to F#. ...
Kapol's user avatar
  • 324
2 votes
2 answers

Implementing blockchain block in C++11

I want to rewrite blockchain source code from Golang to C++11. Please, review my code and help me to improve it. Source in Golang: ...
typemoon's user avatar
  • 183
7 votes
1 answer

A blockchain implementation in 207 lines of code

There is a blockchain class with minimal functionality inspired by naivechain. It has template data and hash function parameters: ...
lisovskey's user avatar
  • 313
2 votes
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Customizable Blockchain's block structure

I'm creating a new open-source blockchain framework for .NET Core and .NET Standard. But I have some questions about how to make block structure to be customizable and look beautiful. Let's begin ...
denismaster's user avatar
4 votes
1 answer

Listens for custom messages on the production Bitcoin blockchain

The application listens for OP_RETURN messages on the Bitcoin blockchain and prints them to standard output. OP_RETURN is a custom transaction locking script that can store data, but nothing beyond ...
weare138's user avatar
  • 541