Data on Chain — Part 3 of 3 · ChainLab The first two parts were about plumbing — how to get free data on and off a chain, and how to feed it to a contract. This part is about the thing you are actually selling. It starts with a structure that shows up everywhere…
Data on Chain — Part 2 of 3 · ChainLab In Part 1 we settled on a reframing: a blockchain does not sell data storage, it sells verifiability and access. Now change one thing. Make the buyer not a person but another smart contract — a lending protocol that needs a property price to value…
Data on Chain — Part 1 of 3 · ChainLab Here is a tempting idea. Public data like real estate transaction prices is free and open. What if you wrapped it, put it on a blockchain, and sold access? The pitch writes itself: “verifiable, tamper-proof property data on-chain.” The idea is worth pursuing, but almost…
Korea’s tech is world-class, so why isn’t AI payment running smoothly here yet? The answer isn’t “skill” — it’s the “traffic lights.” It’s not that our tech falls short Let’s clear up a misconception first. Korea being behind in this field is absolutely not about lacking technology. Experts actually say the opposite: domestic players like…
You’ve probably used “safe payment” on a secondhand marketplace. AI payments need this too. The catch: it’s far harder than it looks. Picture a secondhand deal Ever bought something from a stranger on a marketplace app? It’s nerve-racking. Send the money first and they might not ship the item; ship the item first and they…
If last part’s x402 was a vending machine, these two approaches are closer to a “spending allowance” and a “bar tab.” Recap: who’s holding the wallet? With x402 last time, the AI held its own wallet and paid right there on the spot — like dropping a coin in a machine. Free and fast, but…
Put a coin in a vending machine, out comes a drink. x402 recreates that exact simple exchange on the web. Picture a vending machine Standing at a vending machine is beautifully simple. You drop in a coin, a drink comes out. No sign-up, no ID, no card approval. Just the coin and the drink —…
AI is starting to buy things and pay for them by itself, with no human in the loop. It sounds like science fiction, but it’s already happening. “Go buy that report and summarize it for me” Picture yourself saying this to an AI assistant: “Go find and buy this week’s semiconductor news report, then summarize…
Signature Replay & Operational/Key-Management Failures The final installment. The vulnerabilities in Parts 1–3 mostly had on-chain root causes. Part 4 crosses that boundary. One is a replay attack, where a cryptographic proof — a signature — gets reused out of context. The other is a case where the key management and operations outside the blockchain…
Consensus-Level Attacks & Access Control Failures So far we’ve covered the contract layer (Part 1) and the economic layer (Part 2). Part 3 splits in two directions. One targets the blockchain’s foundation — the consensus algorithm itself (the 51% attack). The other is an access control failure, where a contract fails to properly decide “who…