Scaling Blockchain-Based Tokens with Joint Cryptograhpic Accumulators

The following API for each node in main.js is used to trigger blockchain actions. See the README below for sending HTTP requests and starting nodes.

app.get('/blocks');

// Prints all stats of the blockchain
app.post('/print');

// Prunes each node's local storage of stored JMTs and LMTs
// (ex. after a day of storing them, we can safely prune them)
app.post('/prune');

// Mines the next block of the blockchain by this node.
// Adds any local commitments and LMRs to the JMT 
app.post('/mineBlock'); //req.body.data should be specified to set the block data contents (ex. "Hello World");

// Broadcast this node's locally generated LMR to the network. Store the LMT until it is pruned.
app.post('/broadcastLocalMerkleRoot');

// Get blockchain peers
app.get('/peers');

// Add a new local commitment. This is triggered by the end-user with their commitment.
app.post('/addCommitment'); //req.body.data should be the commitment (ex. "816534932c2b7154836da6afc367695e6337db8a921823784c14378abed4f7d7");

This repository was constructed using a starting template of https://github.com/lhartikk/naivechain. The README of this repository is provided below. See test.js for test scripts regarding Merkle tree generation times.

Naivechain - a blockchain implementation in 200 lines of code

Motivation

All the current implementations of blockchains are tightly coupled with the larger context and problems they (e.g. Bitcoin or Ethereum) are trying to solve. This makes understanding blockchains a necessarily harder task, than it must be. Especially source-code-wisely. This project is an attempt to provide as concise and simple implementation of a blockchain as possible.

What is blockchain

From Wikipedia : Blockchain is a distributed database that maintains a continuously-growing list of records called blocks secured from tampering and revision.

Key concepts of Naivechain

Check also this blog post for a more detailed overview of the key concepts

• HTTP interface to control the node
• Use Websockets to communicate with other nodes (P2P)
• Super simple "protocols" in P2P communication
• Data is not persisted in nodes
• No proof-of-work or proof-of-stake: a block can be added to the blockchain without competition

Naivecoin

For a more extensive tutorial about blockchains, you can check the project Naivecoin. It is based on Naivechain and implements for instance Proof-of-work, transactions and wallets.

Quick start

(set up two connected nodes and mine 1 block)

npm install
HTTP_PORT=3001 P2P_PORT=6001 npm start
HTTP_PORT=3002 P2P_PORT=6002 PEERS=ws://localhost:6001 npm start
curl -H "Content-type:application/json" --data '{"data" : "Some data to the first block"}' http://localhost:3001/mineBlock

Quick start with Docker

(set up three connected nodes and mine a block)

docker-compose up
curl -H "Content-type:application/json" --data '{"data" : "Some data to the first block"}' http://localhost:3001/mineBlock

HTTP API

Get blockchain

curl http://localhost:3001/blocks

Create block

curl -H "Content-type:application/json" --data '{"data" : "Some data to the first block"}' http://localhost:3001/mineBlock

Add peer

curl -H "Content-type:application/json" --data '{"peer" : "ws://localhost:6001"}' http://localhost:3001/addPeer

Query connected peers

curl http://localhost:3001/peers