Welcome to PandaCoin!

PandaCoin is a minimalist implementation of a layer 1 cryptocurrency similar to Bitcoin. It is designed with utmost simplicity and user friendliness in mind and is written from the ground up in C++ — it isn't yet another re-packaging of existing open-source blockchain code (where's the fun in that?!).

Circulation

PandaCoin's are minted by miners who earn a reward of 50 bamboo per block. Mining payments occur up until block 2,000,000 after which miners are compensated purely through transaction fees. This means the total circulation of the currency is limited to 100,000,000 Bamboo.

Technical Implementation

PandaCoin is written from the ground up in C++. We want the PandaCoin source code to be simple, elegant, and easy to understand. Rather than adding duct-tape to an existing currency, we built PandaCoin from scratch with lots of love. There are a few optimizations that we have made to help further our core objectives:

Switched encryption scheme from secp256k1 (which is used by ETH & BTC) to ED25519 -- results in 8x speedup during verification and public keys half the size.
Transactions are created uniquely to each blockID
Can queue transactions to execute up to 10 blocks in the future.
5000 transactions per block, 30 second block time
Measured transactions per second > 400TPS

API

GET: /block_count : Returns the number of blocks in the current chain
GET: /stats : Statistics on current chain in JSON format
GET: /block/<int:blockId> : Block information in JSON format
GET: /ledger/<string:walletAddress> : The balance for the specified wallet in JSON format
GET: /mine : Returns the last block hash and difficulty in JSON format
GET: /sync/<int:startId>/<int:endId> : Returns binary serialized blocks within range
GET: /synctx : Returns binary serialized transactions in mem pool
POST: /submit : Submits a new block (data must be binary serialized)
POST: /add_transaction : Submits a new transaction (data must be binary serialized).

Serialization formats

struct BlockHeader {
    int id;
    time_t timestamp;
    int difficulty;
    int numTransactions;
    char merkleRoot[32];
    char nonce[32];
};

struct TransactionInfo {
    int blockId;
    char signature[64];
    char signingKey[32];
    time_t timestamp;
    char nonce[8];
    char to[25];
    char from[25];
    long amount;
    long fee;
    bool isTransactionFee;
};

Getting Started

Building

Requires:

CMake
Conan package manager (http://www.conan.io)
LevelDB

git clone https://github.com/mr-pandabear/panda-coin.git
cd panda-coin
git checkout stable
mkdir build
cd build
conan install ..
cd ..
cmake .

To compile the miner run the following command:

make miner

You will also need the keygen app to create a wallet for your miner:

make keygen

To compile the node server:

make server

Usage

Start by generating keys.json. Keep a copy of this file -- it contains pub/private keys to the wallet that the miner will mint coins to.

./bin/keygen

To start mining:

./bin/miner

To host a node:

./bin/server

crodnun/panda-coin