🏧 ATM Simulation System using C++

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🚀 Overview

This project simulates a simple ATM system built in C++ featuring:

• Two user types: Account Holders & Admin
• Basic PIN-based authentication with XOR encryption
• Object-Oriented Design: Classes, inheritance, encapsulation

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👥 User Roles

👤 Account Holder

• Log in with PIN
• View account details
• Withdraw & Deposit money

🛡️ Admin

• Secure login
• View admin credentials
• Reset any user's balance

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🔑 Core Functionalities

• PIN Encryption:
  encryptDecrypt() uses XOR with a key for basic PIN protection.

• AccountHolder Class:
  Stores account number, name, balance, encrypted PIN.
  Methods:

  • verifyPin() – Check PIN (after decryption)
  • withdraw() – Deducts balance
  • deposit() – Adds to balance
  • showDetails() – Displays account info

• Admin Class:
  Inherits from AccountHolder.
  Methods:

  • showDetails() – Displays admin info
  • resetBalance() – Modify user balance

• ATM Class:
  Handles user interaction & operations.
  Methods:

  • accessAccount() – Login, view, withdraw, deposit
  • findAccount() – Search by name/account number

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⚙️ Features

• OOP Principles: Classes, inheritance, encapsulation
• Simple Authentication: PIN-based, encrypted storage
• Admin Controls: User management & balance resets
• Interactive Input Loop: Multiple operations per session

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🧩 Example Test Case

User Login:

1. Enter account number or name (e.g., John Doe)
2. Enter PIN (e.g., 1234)
3. View balance, withdraw, deposit

Admin Login:

1. Enter admin PIN (admin)
2. Reset any user's balance

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⚠️ Potential Issues & Suggested Improvements

Issue	Description & Suggestions
🔒 Weak PIN Encryption	XOR w/ single key is insecure. Use modern hashing (SHA-256)
💾 No Data Persistence	Data lost on exit. Use files or DB for real storage
🚫 Limited Error Handling	Add input validation (e.g., negatives, non-numeric input)
🛡️ Admin Inheritance	Admin inherits AccountHolder, but may not need balance
🧹 Input Stream Handling	Careful use of cin.ignore() to avoid input glitches

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📚 Quick Start

g++ atm_simulation.cpp -o atm_simulation
./atm_simulation

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📝 Summary

A well-structured demonstration of OOP in C++ with user/admin roles, basic encryption, and ATM functionalities.
For real-world use:

• Improve security
• Add persistent storage
• Enhance input validation

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🎯 Try it, extend it, and make banking fun (and secure)! 🚀