Courses
1. Introduction to Blockchain and Solana
2. Setting Up Your Development Environment
3. Solana Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Solana Programs
6. Building Your First Solana Program
7. Deploying Programs on the Solana Network
8. Interacting with Solana Programs
9. Using Solana CLI and SDKs
10. Developing Decentralized Applications (DApps)
11. Smart Contract Security Best Practices
12. Testing and Debugging Solana Programs
13. Optimizing Performance on Solana
14. Exploring Solana Ecosystem Tools
1. Introduction to Blockchain and Polygon
2. Setting Up Your Development Environment
3. Polygon Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Smart Contracts on Polygon
6. Building Your First Smart Contract on Polygon
7. Deploying Smart Contracts on the Polygon Network
8. Interacting with Smart Contracts on Polygon
9. Using Polygon CLI and SDKs
10. Developing Decentralized Applications (DApps) on Polygon
11. Smart Contract Security Best Practices for Polygon
12. Testing and Debugging Smart Contracts on Polygon
13. Optimizing Performance on Polygon
14. Exploring Polygon Ecosystem Tools
1. Introduction to Cybersecurity
2. Report Writing for Penetration Testers
3. Information Gathering
4. Vulnerability Scanning
5. Introduction to Web Applications
6. Common Web Application Attacks
7. SQL Injection Attacks
8. Client-Side Attacks
9. Locating Public Exploits
10. Fixing Exploits
11. Antivirus Evasion
12. Password Attacks
13. Windows Privilege Escalation
14. Linux Privilege Escalation
15. Advanced Tunneling
16. The Metasploit Framework
17. Active Directory: Introduction and Enumeration
18. Attacking Active Directory Authentication
19. Lateral Movement in Active Directory
1. JavaScript Prototype Pollution
2. Advanced Server-Side Request Forgery (SSRF)
3. Web Security Tools and Methodologies
4. Source Code Analysis
5. Persistent Cross-Site Scripting
6. Session Hijacking
7. .NET Deserialization
8. Remote Code Execution
9. Blind SQL Injection
10. Data Exfiltration
11. Bypassing File Upload Restrictions and File Extension Filters
12. PHP Type Juggling with Loose Comparisons
13. PostgreSQL Extension and User-Defined Functions
14. Bypassing REGEX Restrictions
15. Magic Hashes
16. Bypassing Character Restrictions
17. UDF Reverse Shells
18. PostgreSQL Large Objects
19. DOM-Based Cross-Site Scripting (Black Box)
20. Server-Side Template Injection
21. Weak Random Token Generation
22. XML External Entity Injection
23. RCE via Database Functions
24. OS Command Injection via WebSockets (Black Box)
Understanding Smart Contracts
Ethereum · Chapter 5
Understanding Smart Contracts
A smart contract combines stored data with functions that read or change it. Its rules apply even when someone bypasses your website and calls the contract directly.
The basics
- A state variable stores information onchain. A function defines an action, such as increasing a counter.
- A view function reads state without changing it. A transaction is needed to persist a change.
- Contract data is public, including variables marked private. Private limits access from other Solidity code; it does not encrypt stored information.
Try it yourself
Design a counter with one value and one increment action. Decide whether anyone can increment it. Our learning example allows everyone, making the rule easy to observe.