weberius/jblockchain-government

A fork of JBlockchain with many enhancements as example for a Blockchain 3.0 for administration of citizens

jblockchain government

@author Philip Kretz

@email ich ( at ) philipkretz . de

@date 2018-07-10

This is a fork of the JBlockchain project (https://github.com/neozo-software/jblockchain).

Much thanks to Neozo for his work!

I forked and extended his demo project for creating a new blockchain in Java which you can also use for productive private (or public) blockchains. Here I added a demo case as use in a decentral blockchain government for handling purposes of normal citizens. Citizens can be added to the blockchain, their marriage or divorce can be added as social status. Also their new born children can be added or citizens can be declared or alive. Thus a whole society can simply control itself via a blockchain 3.0. The blockchain can and should be fitted and compiled to your special needs. Forks are welcome under Apache 2.0 license.

Fork License-Appendix:

Copyright 2018, Philip Kretz

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Additional features and changes to the original JBlockchain:

• saving CPU power and voltage by replacing SHA256-algorithm with SCrypt
• added a more complex self ip discovery algorithm similar to Bitcoin
• added a backbone network of trusted root servers, which must be added in config class
• blockchain and entity data are saved, so hosts can go offline (json.gz files)
• saving disk space and data transfer size with gunzip algorithm for transferring and saving data
• added multiple config parameters for client that you must not submit address for communication with nodes
• added a blockchain government as demo case in client
• keys and blockchain files are saved in folder HOME/blockchain

build

- edit config class and files for setting port (default: 21986) and root servers (default: only localhost)

- fit code for your needs (optional)

cd jblockchain-government ./mvnw package

Note: if jar-files do not get generated, it can be a solution to run "mvn clean install" from project main folder!

please respect: all json.gz for blockchain files will be deleted after compiling because of unit test case issues, so please create a backup if you change something!

This builds these 3 Spring Boot/Maven modules:

• node: part of the blockchain network for handling proof of work mining algorithm, building blocks and distributing transactions
• client: a shell client to communicate to local blockchain node
• common: Shared code with entities used by the other 2 components

start node (needed for running)

java -jar node/target/node-0.0.1-SNAPSHOT.jar

maintaining commands

this starts the mining process of a local node

java -jar client/target/client-0.0.1-SNAPSHOT.jar --start-miner

this stops the mining process of a local node

java -jar client/target/client-0.0.1-SNAPSHOT.jar --stop-miner

write commands:

Generate keypair in folder HOME/blockchain (call just only once)

This generates key.priv and key.pub files for user (as you should know in encryption: never share your key.priv-file and keep it as safe as possible).

The local node will distribute this new public address to all other nodes by invoking the publish-address command.

Note the sender id as result of this command for sending messages and keep it with your key files!

For every manipulating message command you will have to add an address hash as sender.

If you did not note it, you will find it via http://localhost:21986/address at the bottom of the list ;-)

Ensure that this is also the hash of your key-files or pick the correct one!

cd client/target java -jar client-0.0.1-SNAPSHOT.jar --keypair

add an address to blockchain (normally just needed once)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --publish-address --publickey key.pub

sending messages (just for explanation, normally not needed)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --transaction --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --message "Hallo Welt" --privatekey key.priv

sending special JBlockchain government messages (Kept really simple, I know...)

add a new city (for what do you need a postcode if you have a blockchain id?)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --add-city --city "Springfield" --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

add a new street

java -jar client/target/client-0.0.1-SNAPSHOT.jar --add-street --name "Simpson av." --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

add a new house

java -jar client/target/client-0.0.1-SNAPSHOT.jar --add-house --houseNr 23 --street "Simpson av." --city "Springfield" --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

add a new citizen

java -jar client/target/client-0.0.1-SNAPSHOT.jar --add-citizen --firstName Homer --lastName Simpson --birthday 19540204 --father "Grandpa Simpson" --mother "Unknown" --address "Simpson av. 23, Springfield" --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

change address of a citizen

java -jar client/target/client-0.0.1-SNAPSHOT.jar --set-address --firstName Bart --lastName Simpson --address "Tree house" --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

note a marriage (hopefully forever)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --marriage --person1 "Homer Simpson" --person2 "Marge Simpson" --date 19740523 --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

note a divorce (hopefully not)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --divorce --person1 "Whitney Tears" --person2 "Lars Vegas" --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

declare death of a citizen (the sad part - I hope)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --declare-death --firstName Pablo --lastName Escobar --date 19930212 --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

declare a citizen alive after death (if a mistake occures, a lost person gets found or also after 3 days for Jesus)

java -jar client/target/client-0.0.1-SNAPSHOT.jar --declare-alive --name Jesus --sender "Tdz0bKDfca3QjFAe5Ccuj9Noy6ah8n+R8DnZznvjic4=" --privatekey key.priv

read commands:

list all cities

java -jar client/target/client-0.0.1-SNAPSHOT.jar --show-cities

list all citizens to a city

java -jar client/target/client-0.0.1-SNAPSHOT.jar --show-citizens --city Springfield

show all details saved to a citizen

java -jar client/target/client-0.0.1-SNAPSHOT.jar --show-citizen-details --name "Homer Simpson" --city Springfield

show birth death rate to a city

java -jar client/target/client-0.0.1-SNAPSHOT.jar --show-birth-death-rate --city Springfield

Hint: the whole blockchain can be viewed in blockchain.json.gz file or via http://localhost:21986/block

Addresses and connected nodes can be seen in http://localhost:21986/address and http://localhost:21986/nodes (or also in files)

Newer transactions which are still not collected in a block can be viewed at ttp://localhost:21986/transaction (or file transaction.json.gz)