PQBlockchain

This application is part of my Bachelor's thesis. For in-depth details, see the technical report.

This application works as a blockchain client. The idea was to create a blockchain that would use the new post-quantum cryptography and be resistant to quantum attacks. The main goal was to test the performance of post-quantum algorithms within a blockchain.

Repository contents

In other folders of this repository are additional README files, which provide a more in-depth explanation of their content.

Folder	Content
./doc	Doxygen, documentation, technical report, LaTeX sources, images, logo, poster
./src	Application source code
./extern	External libraries
./tests	Application unit tests
./scripts	Scripts for automatic testing

Requirments

The application was tested on Linux Ubuntu 22.04

• gcc compiler
• C++ 20
• CMake 3.28
• Python 3.10 (for testing)
• Docker (for testing)

External Libraries

Library	Licence	Usage
Crypto++	BSD 3-Clause License	SHA-512, Ed25519, and ECDSA algorithms
GoogleTests	BSD 3-Clause License	Unit testing
nlohmann JSON	MIT	JSON file parsing
LevelDB	BSD 3-Clause License	Embeded key-value database
PQClean	Custom	Post-quantum algorithms for digiral signatures
SPD log	MIT	Management of application logs

Build

WARNING: Make sure that all commands are executed from the root folder of this repository (The project and applications are using relative paths!).

make commands

Command	Action
setup	Create tmp and build directories
make	Configure and compile (might be required to be run twice)
configure	Generate CMake configuration (might be required to be run twice)
compile	Compile the project and external libraries
run	Run the main application. Requires arguments for the program make run ARGS=<program_arguments>
test	Run one test suit. Requires name of test suit as argument make test ARGS=<test_suit_name>
testall	Run all test suits
clean	Remove temporary files created by main application/tests and generated documentation
cleanall	Remove whole build and generate temporary files
doc	Generates Doxygen documentation

Compilation

For configuration and compilation run: make (It is possible that the first run of make will fail. In that case, it is necessary to run the make command again a second time.)

To clean all generated files, use the command make cleanall

Usage

The compiled application is located in ./build/src/App/pqb. The program help can be printed to the console with ./build/src/App/pqb -h/--help or make run ARGS="-h/--help"

There is one required argument:

• -s/--sig <signature_algorithm> - Name of the signature algorithm to use. There are implemented algorithms: falcon512, falcon1024, dilithium2, dilithium3, dilithium5, ed25519 and ecdsa.

and one optional argument is:

• -c/--conf <path_to_wallet_configuration_file> - Select the wallet configuration file. If not used, the default path is in the local directory tmp/conf.json.

Examples:

Note that before running the application tmp folder has to be created in the repository root folder. The guid how to establish multiple nodes at once with Docker is described here.

Run the application

make run ARGS="-s falcon512"
./build/src/App/pqb -s falcon512

Run the application with the configuration file

make run ARGS="-s falcon512 -c tmp/conf1.json"
./build/src/App/pqb -s falcon512 -c tmp/conf1.json

Consol interface

After the application starts, it opens the databases and wallet configuration file (if they do not exist, it creates them). Then the application establishes connections with its peer on the UNL list (see technical report) and commands for the application can be input to the console.

Application supports this commands:

Command	Arguments	Action
createTx	<amount> <receiver_address>	Create a transaction
whoami	None	Print address of local wallet
walletTxs	None	Print transactions made with the local wallet or received by this wallet
blocks	None	Print list of blocks in the database
blockTxs	<block_id>	Print transactions in block with given block_id
accs	None	Print list of accounts in the database
chain	None	Print the chain of blocks
conns	None	Print currently established connections
echo	<string>	Just return the imputed string (for testing purposes)
exit	None	Close the application