GROUP 49 - Blockchain Assignment 1

Land Management System

A blockchain based land management system using the PoET consensus algorithm.

Important

Run Main.py to start. The PoET algorithm is implemented in file Poet.py

Features

• Ability to register new users to the system with previously owned property. (implemented in file Register.py)
• User can buy and sell a property. (implemented in file Main.py in the AddTransac() function)
• Incorporation of 'Proof of Elapsed Time' consensus algorithm to improve the security of the blockchain. (implemented in file Poet.py)
• Implementation of Merkle root to calculate the hash of all the transactions in a block. (implemented in file Merkle.py)
• Users can view the transaction history that is related to a property. (implemented in file Search.py)

Code Components

Block

Parameter	Type	Description
timestamp	int	Autogenerated time stamp
prevhash	string	The hash of the previous block
data	string	The transaction data to be stored in the block.
poet	string	The hash of [prev_block_hash + block_data + merkle_root] generated by the winner via Proof of Elapsed Time.

Functions

Blockchain.py

Functions	Description
ProofOfElapsedTime(self, prev_hash: str, data: list)	calls poet to get the winner node, and returns the block hash. [prev hash + block data + merkle root]
AddTransaction(self, t: Transaction)	adds a transaction to the transaction pool, a new block is added if entries in pool >= 4
verifySignature(self, S, pus, M)	verifies if the transaction was done by the correct user by using cryptography
AddBlock(self)	mines a new block, if all the transactions are verified the block is added to the blockchain

Create.py

Functions	Description
Create()	Initialises a new blockchain

Main.py

Functions	Description
AddTransac()	Takes transaction details from user to add to blockchain

Merkle.py

Functions	Description
Merkle(transactions: list)	Hash all the transactions in the list and append them to a new list
MerkleRoot(state)	Recursive hashing to get merkle root.

Poet.py

Functions	Description
Poet()	Asynchronous function to implement proof of elapsed time algorithm
NodeWait(node: str, delay: float)	Asynchronous function to make a node wait for delay time

Register.py

Functions	Description
createPublicKey(e_public_keys, p_public_keys)	Creates and returns public key of user using cryptography
createKeys(p_public_keys)	Creates and returns public and private key of user using cryptography
Register()	Registers a new user by creating a new node for the user

Search.py

Functions	Description
Search(blockChain)	Prints the transaction history of the property id given as input from the blockchain

Group Details

GROUP 49

Name	ID
Kaustubh Bhanj	2019A7PS0009H
Dhruv Gupta	2019B3A70487H
Gaurav Sinha	2019A7PS0131H
Bokkasam Venkata Sai Ruthvik	2019A7PS0017H