This project is a Python-based reference implementation of BBc-1, a trustable system of record keeping beyond blockchains.
The design paper (white paper) and the analysis paper are available here and here. BBc-1 is inspired from blockchain technologies like Bitcoin, Ethereum, Hyperledger projects, and so on. BBc-1 is a simple but reliable distributed ledger system in contrast with huge and complicated existing blockchain platforms. The heart of BBc-1 is the transaction data structure and the relationship among transactions, which forms a graph topology. A transaction should be signed by the players who are the stake holders of the deal. BBc-1 achieves data integrity and data transparency by the topology of transaction relationship and signatures on transactions. Simply put, BBc-1 does not have blocks, and therefore, requires neither mining nor native cryptocurrency. BBc-1 can be applied to both private/enterprise use and public use. BBc-1 has a concept of domain for determining a region of data management. Any networking implementation (like Kademlia for P2P topology management) can be applied for each domain. Although there are many TODOs in BBc-1, this reference implementation includes most of the concept of BBc-1 and would work in private/enterprise systems. When sophisticated P2P algorithms are ready, BBc-1 will be able to support public use cases.
The source codes in this repository is a platform of BBc-1 and bbc_core.py is the main process of a core node. The APIs of BBc-1 is defined in bbc_app.py and bbclib.py. So application developers should import them in your apps. For building a BBc-1 system, bbc1 package needs to be installed in the hosts and you need to run bbc_core.py on each host. In order to configure the BBc-1 network, the utilities in utils/ directory are available. They are a kind of BBc-1 application, so that you can develop your own management tools.
For the details, please read documents in docs/ directory. Not only documents but slide decks (PDF) explain the design of the BBc-1 and its implementation.
Installing bbc1 through pip sometimes fails owing to pip cache trouble. It might occur in the case that you terminate the install process during libbbcsig building process. This leads to a defect in the pip cache of libbbcsig module, and resulting in fail installing forever.
To solve the problem, you need to remove pip cache or pip install without using cache. How to solve it is explained below.
Removing pip cache directory is a fundamental solution to this problem. The cache directories in various OS platform are as follows:
After removing the cache directory, install bbc1 module again.
python3 -mvenv venv . venv/bin/activate pip install bbc1
Disabling cache and re-installing the module is another solution, which is easier way.
python3 -mvenv venv . venv/bin/activate pip --no-cache-dir install -I bbc1
In the update to v1.3, a meta table of DB is updated to support timestamp-based search. The main table for transaction data itself remains unchanged, so that just updating meta table is need for migration. Migration tool is provided by utils/db_migration_tool.py. How to migrate is described below.
Install new module by pip command if you use pip bbc1 module. Then, stop the old bbc_core.py process and start new one. The meta table of DBs are automatically upgraded when the new bbc_core.py boots up.
Run db_migration_tool.py by specifying target working directory. If using pip module, the tool can be invoked directly as follows:
db_migration_tool.py -w 'working_dir'
You will see records are upgrading by the tool. In the case of high transaction rate, some records might remain unchanged. In that case, re-run the tool.
Note that you have to perform step 1 and 2 for each working directory because the process reads config file in the working directory and upgrades the DBs specified in the config.
Some documents are available in docs/.
cd docs/api/_build/html pipenv run python -m http.server
python -mvenv venv
tools for macOS by Homebrew
brew install libtool automake python3 pip3 install virtualenv
tools for Linux (Ubuntu 16.04 LTS, 18.04 LTS)
sudo apt-get update sudo apt-get install -y git tzdata openssh-server python3 python3-dev python3-pip python3-venv libffi-dev net-tools autoconf automake libtool libssl-dev make
Install development tools (libtool, automake)
Install python and pip
Clone this project
Prepare OpenSSL-based library in the root directory
Install dependencies by the following command (in the case of python 3.6)
python -mvenv venv source venv/bin/activate pip install -r requirements.txt
Start bbc_core.py on a terminal
cd core python bbc_core.py
Start a sample app in another terminal (should be initially at bbc1/ top directory)
pipenv shell cd examples python file_proof.py arg1 arg2..
python -mvenv venv source venv/bin/activate pip install bbc1
or, if you just want to use BBc-1,
cd docker ./docker-bbc1.sh gitbuild
cd docker ./docker-bbc1.sh pipbuild
The initial password is "bbc1".
ssh -p 10022 root@localhost
The working directory of BBc-1 on the docker container is mounted on docker/data/.bbc1/. You will find a config file, ledger DB and file storage directory in the working directory.