@RealJohnnyTime

Founder @ https://xitter.cf/t.co/gcgrMm5l8P, JohnnyTime @ Youtube, Securing Web3 @ https://xitter.cf/t.co/wJdpJyYK5y & https://xitter.cf/t.co/3d9aL8nDvG

 Web3
johnnytime.xyz/
Joined February 2012
  • Tweets10.6K
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JohnnyTime 🤓🔥 retweeted
Jobb@jobb_0446m
Just finished Fungible Tokens and Non-Fungible Tokens in @RealJohnnyTime's course. Writing, deploying, and testing these tokens are now a piece of cake. You can check out his course here: smartcontractshacking.com/

Smart Contract Hacking Course 2026 | Smart Contract Auditing Training

Master smart contract hacking and auditing with hands-on exercises, AI-augmented workflows, and practical blockchain security training.

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New SCH CTF Arena challenge: Shop. Worth 975 EXP and up to 1475 HP. smartcontractshacking.com/to…

Shop Ethernaut CTF Challenge | SCH

Review the intermediate Ethernaut Shop Solidity challenge, inspect its vulnerable contract, and unlock the Foundry exploit workspace as you progress.

smartcontractshacking.com
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We've updated mobile layouts, dark mode, course navigation and progress displays. Submitting a quiz answer now also shows loading feedback. Students: is there a particular screen or action that's still frustrating to use?
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Study one hack by answering four questions: What did the attacker control? What did the protocol trust? Which transaction crossed that boundary? What changed? Link the evidence. Leave unknown details unknown.
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A bonding-curve token can rise in price while exits become fragile. Model a buy wave followed by a sell-off; check reserves and execution prices. Try the SCH stress tester: smartcontractshacking.com/to…

Bonding Curve Stress Tester | Bonding Curve Calculator for Tokenomics Risk

Free bonding curve stress tester for tokenomics teams, auditors, and founders. Model bonding curve math, buy and sell shocks, slippage, reserve pressure, and manipulation risk in one interactive...

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Replying to @0x_FiliSec
Of course! Always!
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Replying to @jobb_04
Amazing work!
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LFG!
Jobb@jobb_04Oct 24
vm.prank allowed me to run my tests correctly. I tried finishing the exercises without AI and looking at the solutions. Fungible Tokens Exercise 1 conquered! Thanks, @RealJohnnyTime! Looking forward to finishing the whole SCH course before 2026 ends.
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Great thread!
Jobb@jobb_04Oct 24
6 Lessons I learned while finishing the Fungible Tokens exercises from @RealJohnnyTime's SCH
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An AI writes a smart contract, then reviews it: "Who wrote it?" "The model." "Who reviewed it?" "The model." "What happens if the withdrawal fails?" "Hang on."
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4/4 Coinbase's analysis of the historical Nomad exploit: coinbase.com/blog/nomad-brid… The blank passport illustration is a metaphor for accepting an unproven message.

Nomad Bridge incident analysis

TLDR: Building a better crypto ecosystem means building a better, more equitable future for us all. That’s why we are investing in the larger community to make sure anyone who wants to participate in...

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3/4 Copycats reused transaction data with different recipients. Test a message that has never entered the proof process. Follow its default storage value through validation; an unknown entry must not grant permission.
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2/4 Looking up an unknown message returned bytes32(0). An initialization change had made that zero root acceptable. The unproven message passed the root check, allowing a payout.
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Nomad's bridge paid out on unproven messages in August 2022. Bridge messages authorize actions such as releasing funds on another chain. An unknown message passed Nomad's validation because its default value was treated as trusted. 1/4
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You can now find your course's exercise files, solutions and setup lessons under Course Resources. For lesson questions or account problems, use Get Help on the dashboard.
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Full guide: smartcontractshacking.com/at…

Weak Randomness in Smart Contracts: Blockhash Exploits + VRF Fixes (2026) | SCH

Weak randomness from block.timestamp is predictable. Learn how attackers game on-chain lotteries and NFT mints, and the Chainlink VRF solution.

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Hashing public block data doesn't make it unpredictable. Follow the inputs in this diagram.
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Free Rider hides a plain accounting bug inside a flash swap. buyMany passes the same msg.value into every purchase. 15 ETH can satisfy six purchase checks. That detail lets the attacker take every NFT. youtube.com/watch?v=cxFH9U1N…

Damn Vulnerable DeFi V4 (Foundry) Free Rider Solution (Challenge 8) - Solutions Walkthroughs

Welcome to the walkthrough of Challenge #10 in the Damn Vulnerable ...

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Hack totals need incident sources. Audit-firm claims need reports. We built two tools so readers can check both for themselves. smartcontractshacking.com/to… smartcontractshacking.com/to…

Crypto Hack Statistics & Web3 Security Trends | SCH

Track reported Web3 hacks, losses, attack methods, and affected chains over time. Compare periods and inspect the incidents behind every trend.

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New SCH CTF Arena challenge: Denial. Worth 1150 EXP and up to 1750 HP. smartcontractshacking.com/to…

Denial Ethernaut CTF Challenge | SCH

Review the advanced Ethernaut Denial Solidity challenge, inspect its vulnerable contract, and unlock the Foundry exploit workspace as you progress.

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