Tiny-Blockchain

This is a small blockchain based on "Bitcoin and Cryptocurrency Technologies" book from here. It uses crow library for rest apis. crow. It is a very fast and easy to use C++ micro web framework (inspired by Python Flask). For the JSON manipulation, I used JSON for Modern C++, nlohmann/json, nlohmann/json. And for calculating sha256, I used sha256.h from Zedwood.

How to compile:

mkdir build
cd build
cmake ..
make

To run a node on port 6000:

./bc 6000

To get chain from current node:

localhost:6000/chain

To mine from current node:

localhost:6000/mine

New transaction is a POST method, make sure to add to its body like this:

{
    "sender": "x",
    "recipient": "y", 
    "amount":1
}

To add a new transaction:

localhost:6000/transaction/new

{
    "nodes":["localhost:6001", "localhost:6002"]
}

To register other nodes in the network:

localhost:6000/nodes/register

To solve conflicts between current nodes, use resolve nodes, it keeps the longest chain:

localhost:6000/nodes/resolve

Each node, at first, creates the genesis block with no transactions. Then it keeps the current transactions until a mine happens. Then it adds a new block to the chain with transactions.

Here is a complete example:

Run an instance with port 6000, ./bc 6000, then add some transactions, then a mine, some other transactions and some other mines, now check the chain with localhost:6000/chain. Now, it's time to add another instance with port 6001, and register other nodes to it. Right now, this one has a smaller chain, so we expect that its chained replaced with the others chain. Run resolve request and see the result.

VHPL-UIS/Tiny-Blockchain