Social-Chain

Idea

Social Chain is an implementation of blockchain for social cause. This chain aims to decentralise and transparentize the process of crowd funding. The target of the project is to let the contributors see where their donated money are invested and/or to whom they are given, hence the frauds can be prevented. The transactions are also secured due to mechanism of blockchain. Apart from social cause, the chain after adding some functionalities can also be used for multiple B2B transactions which will be further discussed and integrated.

Installation

1. Make sure Python 3.6+ is installed
2. Git clone

$ git clone https://github.com/harsh-2711/Social-Chain.git
$ cd SocialChain

3. Create a virtual environment (recommended)

$ virtualenv env

NOTE: If virtual environment isn't installed on the local system the do -

$ pip install virtualenv

4. Activate virtual environment

$ source env/bin/activate

NOTE: To deactivate the virtual environment use

$ deactivate

5. Install requirements

$ pip install requirements.txt

Project Structure

• Blockchain.py - All the functions ehich are needed to build a blockchain

• app.py - Code to create Flask APIs for using the SocialChain

• account.py - Functions related to account maintenance of a user

• database.py - Functions related to creation and maintenance of database (Used mainly during transactions)

• model.py - Basic class to provide default attribute to database variables

• transactions.py - Contains function for doing local transaction, universal transaction and transfering local transactions to TransferQueue

• data - Database files keeping record of the local and universal transactions

• lib - Basic utilities and hashing algorithms

Using APIs

• Run the app.py file

$ python app.py

• Open the generated localhost in the web browser. If it shows the message App is deployed then the app is good to go

• Following are the commands that you can enter after the localhost URL to use the SocialChain

Queries	Request	Params	Response Message
/new_account	GET	NONEED	Public and private key along with address
/get_account	GET	NONEED	Latest account credentials
/mine	GET	NONEED	Details of the new block forged
/transactions/new	POST	sender, receipent, amount	Local block number where transaction is saved
/transactions/add/queue	POST	Hash or local index of transaction	Added successfully or error message (if incorrect values)
/chain	GET	NONEED	Get full chain
/nodes/register	POST	IP of nodes	List of nodes added
/nodes/resolve	GET	NONEED	If the local chain is modified or not based on the universal chain

About block

The blockchain is a data structure that is linked sequentially from back to forward by blocks containing transaction information. SHA256 cryptographic hashing is performed on each block header to generate a hash value.

A bitcoin block is as follows:

{
 "size":43560,
 "version":2,

 "previousblockhash":"00000000000000027e7ba6fe7bad39faf3b5a83daed765f05f7d1b71a1632249",
 "merkleroot":"5e049f4030e0ab2debb92378f53c0a6e09548aea083f3ab25e1d94ea1155e29d",
 "time":1388185038,
 "difficulty":1180923195.25802612,
 "nonce":4215469401,
 "tx":["257e7497fb8bc68421eb2c7b699dbab234831600e7352f0d9e6522c7cf3f6c77",
  #[...many more transactions omitted...]
  "05cfd38f6ae6aa83674cc99e4d75a1458c165b7ab84725eda41d018a09176634"
 ]
}

A SocialChain block is as follows:

{
"index": 3,
"timestamp": 1558212779,
"transactions": [
  {
  "timestamp": 1558212779,
  "sender": "0",
  "recipient": "e9c7bd1b754d4cd99330fcff1262cafa",
  "amount": 0.033,
  "hash": "6df21f684de8c9ddb360b69cf2970117ccef8248f80f3098f4403a8e058dc9b0",
  "localIndex": 0
  },
  "tx": ["257e7497fb8bc68421eb2c7b699dbab234831600e7352f0d9e6522c7cf3f6c77",
        #[...many more transactions omitted...]
  ], 
"proof": 82082,
"previous_hash": "24ad9452cde3e9f7451f4afaa402f98892716edb849c3ba9ae96785e2f804c68"
}

Comparing the two blocks, it is evident that the SocialChain block contains more information then normal bitcoin block.