Detailed Report

Introduction:
     This report presents the implementation of a basic blockchain data structure using C++. The 
blockchain consists of blocks, each with unique hash and pointer to the previous block in the chain.
Each block contains a list of transactions represented as a linked list.

Blockchain Implementation:
     Transaction Structure: A structure defining the properties of a transaction, including the 
     Sender, Receiver and Amount.
     
     Block Structure: A structure defining the properties of a block, including a vector of 
     transaction(Amount), the previous block's Hash (previoushash) and current hash (hash).
     
     Blockchain Class: A class representing the blockchain, which manages the chain of blocks and 
     provide functionality to add new blocks(addBlock()) and validate the chain(validateChain()).
     
Functionality:

     Initialization: The blockchain is initialized with a genesis block containing no transactions
     and a hash value "0".
     
     Adding Blocks: The blockchain allows the addition of new blocks by providing a list of 
     transactions. The new block's hash is calculated based on the previous block'c hash and it is
     added to the chain.
     
     Validation: The blockchain includes a function to validate the integrity of the chain by 
     verifying that each block's previous hash matches the hash of the previous block.
     
Security Implications: The use of blockchain for financial transactions offers several security
benefits:

     Immutability: Transactions added to the blockchain are difficult to tamper with, ensuring the 
     integrity of the transaction history.
     
     Decentralization: The decentralized nature of blockchain networks enhances security by 
     removing single points of failure and requiring consensus among multiple nodes.
     
     Cryptographic Security: Blockchain networks employ cryptographic algorithms for secure 
     transaction verification, digital signatures, and tamper-evident record keeping.
     
     Transparency: Blockchain transactions are transparent, allowing for auditing and accountability.
     
Conclusion:
     The implemented basic blockchain data structure in C++ provides a foundation for building
more complex blockchain applications. The code demonstrates the creation of blocks, linking them
together, and validating the chain. It serves as a starting point for further exploration and 
development of blockchain systems.



Code Explanation:

1) Includes and Namespace - The necessary header files, 
#include <iostream>
#include <vector>
#include <cstring>
#include <cstdlib>
#include <ctime>
The code also uses the "std" namespace.

2) Transaction Structure - The "Transaction" structure represents a single transaction in the 
blockchain and the three members are Sender name (sender name), Receiver (receiver name) and 
Amount(transaction amount).

3) Block Structure - It represents a single transaction in th blockchain. It contains the hash of
the current block (hash), hash of the previous block (previous block) and vector of transaction
(transactions). The "Block" constructor initilizes these values by taking the transactions and 
the previous hash as parameters. It also includes a helper function "generateRandomHash()" that 
generates a random hash value for the block.

4) Blockchain class - The "Blockchain" class manages the chain of blocks. It has a private members
"chain", which is a vector of "Block" objects. 
 
     Blockchain() - is the constructor that initializes the blockchain with a genesis block the first
     block with no transactions and a hash value of 0.
     
     addBlock() - adds a new block to the chain. It takes a vector of transactions as input, 
     calculates the previous block's hash, and creates a new block with the provided transactions 
     and the previous hash. The new block is then added to the chain.
     
     validateChain() - validates the integrity of the blockchain by traversing the chain and checking 
     if each block's previous hash matches the hash of the previous block. It returns "true" if the 
     chain is valid and "false" otherwise.
     
     printChain() - prints the details of each block in the chain, including the both hash, previous
     hash, and transactions.
     
5)Main Function:
     In the "main()" function, the "srand()" function is used to seed the random number generator.
     Thenm an instance of the "Blockchain" class is created.
     
     Some sample transaction("transactions1", "transactions2" and "transactions3") are created
     as vectors of "Transaction" objects, representing two set of transactions. These transactions 
     are added to the blockchain using the "addBlock()" function.
     
     Finally, the blockchain is printed using the "printChain()" function, and the validity of the 
     blockchain is checked using the "validateChain()" function. The result is printed as "Yes" if 
     the chain is valid and "No" otherwise.