A modular kernel designed for implementing blockchain-based digital currencies
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CryptoKernel is a C++ library intended to help create blockchain-based digital currencies. It contains modules for key-value storage with JSON, peer-to-peer networking, ECDSA & Schnorr key generation, signing and verifying, big number operations, logging and a blockchain class for handling a Bitcoin-style write-only log. Designed to be object-oriented and easy to use, it provides transaction scripting with Lua 5.3, custom consensus algorithms (e.g Proof of Work, Authorised Verifier Round-Robin) and custom transaction types.


We have used Cryptokernel to implement an experimental digital currency called K320. Its name derives from its monetary policy – Milton Friedman’s K% rule at a rate of 320 basis points or 3.2% growth per year (https://en.wikipedia.org/wiki/Friedman%27s_k-percent_rule). This known rate removes the need for trust in the decisions of a central authority, making monetary supply policy completely transparent. K320 is designed to build up the initial money supply relatively quickly then switch to the K% rule for monetary growth.

In K320, blocks are produced every 2.5 minutes. The block reward starts at 100 coins per block, diminishing for 8 years until the year 2025 at block 1,741,620 and a supply of 68,720,300 coins. At this point the block reward switches to a constant 3.2% per year. At 210,240 blocks per year, that is .0000152% of total supply per block as reward. For example, the first block reward after the switch to the constant reward rate will be ~10.45; (0.000000152*68,720,300). For a more detailed description of this see: https://github.com/mit-dci/CryptoKernel/blob/master/src/client/multicoin.cpp#L80

K320 is currently implemented by default when you run the CryptoKernel software.

Building on Ubuntu 16.04

premake5 gmake2

The resulting binary will be in the bin/Static/Debug directory.

It is also possible to compile with other options. See make help and premake5 --help for a list.


See the source files in src/client/ for example usage. CryptoKernel ships with a Proof of Work coin built-in called K320 that works out of the box. For more information about the API check the documentation.

To launch CryptoKernel as K320 with its default setup, simply write:


To get a list of command line RPC commands use:

./ckd help

To make ckd run in daemon mode use:

./ckd -daemon

API Reference

Build the documentation with doxyblocks.

premake5 gmake2 --with-docs


(in no particular order)

  • Load external contract code to avoid duplication when propagating contracts
  • Standardised address format (not just public keys)
  • Pay to MAST transaction type (includes pay to pubkey hash and pay to script hash)
  • BFT consensus module
  • Raft consensus module
  • Proof of Stake consensus module
  • HD key generation
  • Schnorr signature aggregation for transactions