Banu Prasath Sivakumar

Banu Prasath Sivakumar

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+CODE:
+
+#include <iostream>
+#include <vector>
+#include <cstring>
+#include <cstdlib>
+#include <ctime>
+
+//Transaction Structure
+struct Transaction {
+    std::string Sender;
+    std::string Receiver;
+    double Amount;
+
+    Transaction(const std::string& Sender, const std::string& Receiver, double Amount) : Sender(Sender), Receiver(Receiver), Amount(Amount) {}
+};
+
+//Block Structure
+struct Block {
+    std::string hash; //Current Block,
+    std::string previousHash; //Previous Block.
+    std::vector<Transaction> transactions;//Vector of Transactions.
+
+        Block(const std::vector<Transaction>& transactions, const std::string& previousHash) : transactions(transactions), previousHash(previousHash) {
+        hash = generateRandomHash();//Random Hash for Current Block.
+    }
+
+    std::string generateRandomHash() {
+        const std::string characters = "0123456789ABCDEF";
+        const int length = 13;
+        std::string hash;
+        for (int i = 0; i < length; ++i) {
+            int index = std::rand() % characters.length();
+            hash += characters[index];
+        }
+        return hash;
+    }
+};
+
+// Blockchain class
+class Blockchain {
+private:
+    std::vector<Block> chain;
+
+public:
+    Blockchain() {
+        std::vector<Transaction> genesisTransactions;//Genesis Block
+        Block genesisBlock(genesisTransactions, "0");
+        chain.push_back(genesisBlock);
+    }
+
+    void addBlock(const std::vector<Transaction>& transactions) {
+        const std::string& previousHash = chain.back().hash;
+        Block newBlock(transactions, previousHash);
+        chain.push_back(newBlock);
+    }
+
+    bool validateChain() {
+        for (size_t i = 1; i < chain.size(); ++i) {
+            const std::string& previousHash = chain[i - 1].hash;
+            if (previousHash != chain[i].previousHash) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    void printChain() {
+        for (const Block& block : chain) {
+            std::cout << "Block Hash: " << block.hash << std::endl;
+            std::cout << "Previous Hash: " << block.previousHash << std::endl;
+            std::cout << "Transactions: " << std::endl;
+            for (const Transaction& transaction : block.transactions) {
+                std::cout << "Sender: " << transaction.Sender << ", ";
+                std::cout << "Receiver: " << transaction.Receiver << ", ";
+                std::cout << "Amount: " << transaction.Amount << std::endl;
+            }
+            std::cout << "--------------------------" << std::endl;
+        }
+    }
+};
+
+int main() {
+    std::srand(static_cast<unsigned int>(std::time(nullptr))); // Random number generator.
+
+    // Create blockchain
+    Blockchain blockchain;
+
+    // Add some transactions
+    std::vector<Transaction> transactions1 = {
+        {"Banu", "Prasath", 10000.0},
+        {"Prasath", "Sivakumar", 8000.0},
+        {"Sivakumar", "Banu", 9000.0}
+    };
+    blockchain.addBlock(transactions1);
+
+    std::vector<Transaction> transactions2 = {
+        {"Radha", "Logesh", 3000.0},
+        {"Logesh", "Parvatha", 1000.0},
+        {"Parvatha", "Banu", 5000.0}
+    };
+    blockchain.addBlock(transactions2);
+
+    std::vector<Transaction> transactions3 = {
+        {"Raja", "Whisley", 800.0},
+        {"Whisley", "Nirmal", 500.0},
+        {"Nirmal", "Sathish", 900.0}
+    };
+    blockchain.addBlock(transactions3);
+
+    // Print the blockchain
+    blockchain.printChain();
+
+    // Validate the blockchain
+    bool isValid = blockchain.validateChain();
+    std::cout << "Is Valid: " << (isValid ? "Yes" : "No") << std::endl;
+
+    return 0;
+}
+
+OUTPUT:
+
+/tmp/w0VR9Wl4Ea.o
+Block Hash: CFBE079BD5233
+Previous Hash: 0
+Transactions: 
+--------------------------
+Block Hash: 0F7480C7A5549
+Previous Hash: CFBE079BD5233
+Transactions: 
+Sender: Banu, Receiver: Prasath, Amount: 10000
+Sender: Prasath, Receiver: Sivakumar, Amount: 8000
+Sender: Sivakumar, Receiver: Banu, Amount: 9000
+--------------------------
+Block Hash: D5321F1CD236D
+Previous Hash: 0F7480C7A5549
+Transactions: 
+Sender: Radha, Receiver: Logesh, Amount: 3000
+Sender: Logesh, Receiver: Parvatha, Amount: 1000
+Sender: Parvatha, Receiver: Banu, Amount: 5000
+--------------------------
+Block Hash: 0BF3E0354B512
+Previous Hash: D5321F1CD236D
+Transactions: 
+Sender: Raja, Receiver: Whisley, Amount: 800
+Sender: Whisley, Receiver: Nirmal, Amount: 500
+Sender: Nirmal, Receiver: Sathish, Amount: 900
+--------------------------
+Is Valid: Yes
+
+

Detailed Report

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+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.
+