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Writing

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Cryptography and blockchain — from hash functions to 51% attacks2026-05-12

Cryptography from first principles, SHA-256 walked through gate by gate, Merkle trees, ECDSA, proof of work, and the mathematics behind why a 51% attack is technically possible and economically absurd.

22 min·#cryptography#blockchain#sha-256#math

Building a secure chat in Python, with TLS the whole way down2026-05-12

A threaded TCP chat with mutual TLS, self-signed certs minted in Python, the handshake walked through end to end, and an honest list of the security properties this thing does and does not give you.

12 min·#networking#cryptography#python

AllArkive — an offline AI library that refuses to hallucinate2026-05-17

The talk we gave at BSides Melbourne 2026. We built a self-hosted, offline research assistant that enforces hallucination prevention at the API layer — not the prompt. Here is why that architectural choice is the only one that actually works.

14 min·#allarkive#rag#privacy#local-ai#bsides

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Teaching React from zero, one Todo app at a time2026-05-12

A workshop writeup. Two repos — one for setup, one for live coding — taking a room of first-time React users from a blank terminal to a deployed Todo app. Step-by-step, with the thinking I tried to teach behind every commit.

10 min·#react#teaching#frontend

Lock-In: a desk-side embedded focus tracker you can build in a weekend2026-06-09

Every focus tool runs on the laptop you're trying not to get distracted by. I built a physical box instead. Arduino + Raspberry Pi + Gemini vision + a five-state FSM. Under AU$70. Boot-on-power.

14 min·#embedded#arduino#raspberry-pi#python#sit210