Beginners Track Capture the Flag CTF Intro

on YouTube ↗26m

" summary

Hands-on CTF with 12 progressively harder challenges deployed on Optimism where each solved level mints an SVG NFT flag; workshop shows local testing with Hardhat/Anvil and Scaffold-Ethereum extension, then redeploying to Optimism and successfully capturing live flags. Demonstrations include solving challenge 1 by calling registerMe via UI, scripts or Etherscan, and solving challenge 2 by deploying an intermediate contract to bypass a msg.sender vs tx.origin check. Notes that a few teams finished very quickly at DEFCON (30 minutes) while only five or six completed all levels.

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" chapters (37)

1. 0:00Introduction to CTF concept and history
2. 0:48How CTF games work in blockchain context
3. 1:19Why breaking things leads to deeper understanding
4. 1:49Popular Ethereum CTF examples
5. 2:30Defcon CTF experience and results
6. 2:59Introducing ctfbillgill.com challenge platform
7. 3:35How flag NFTs work with SVG images
8. 4:15Scaffold-Ethereum extension setup
9. 4:47Website walkthrough and first challenge
10. 5:21Connecting wallet and checking flags
11. 5:53Installing scaffold-eth CTF extension
12. 6:36Running local blockchain instance
13. 7:17Deploying challenge contracts locally
14. 7:52Examining challenge 1 contract code
15. 8:29Understanding the flag minting mechanism
16. 9:07Debug contract UI demonstration
17. 9:39Solving challenge 1 through UI
18. 10:17Funding account and completing challenge
19. 10:52Alternative methods to interact with contracts
20. 11:28Using AI Ninja contract interface
21. 12:07Solving via script with private key
22. 13:11Testing solution on local network
23. 13:57Running script on Optimism mainnet
24. 14:46Capturing first flag on live network
25. 15:43Introducing challenge 2 requirements
26. 16:18Understanding msg.sender vs tx.origin
27. 16:54Solution approach using intermediate contract
28. 17:50Writing solution contract code
29. 18:42Deploying solution contract locally
30. 19:38Testing solution contract interaction
31. 20:24Deploying solution to Optimism
32. 21:23Switching frontend to Optimism network
33. 22:08Capturing second flag on mainnet
34. 22:58Recommended next steps for learners
35. 23:33Importance of hands-on practice
36. 24:23Estimated completion times for challenges
37. 25:35Demo of AI Ninja contract interface tool

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