Articles

SIGHASH_ANYPREVOUT on Signet: When Signatures Stop Binding to UTXOs

Standard CHECKSIG asks: did you sign for this UTXO? ANYPREVOUT relaxes that.

OP_CAT + OP_CHECKSIGFROMSTACK on Signet — Dynamic Message, Oracle Authorization

Combining concatenation and stack-signature verification for oracle-driven scripts.

OP_INTERNALKEY + OP_CHECKSIGFROMSTACK on Signet — Identity-Bound Authorization

Pure CSFS asks: did someone sign this? IK + CSFS asks: did the owner sign this?

OP_CHECKTEMPLATEVERIFY on Signet — Locking Outputs at UTXO Creation Time

With OP_CAT you assemble data. With OP_CSFS you authorize it. With OP_CTV you enforce it.

OP_CHECKSIGFROMSTACK on Signet — Sign Anything, Verify on Stack

Satoshi disabled OP_CAT in 2010. OP_CSFS was never even enabled. We ran it on-chain in 2026.

OP_CAT on Signet — Concatenation, Commitment, and Bitcoin Inquisition

Satoshi disabled it in 2010. We ran it on-chain in 2026.

The Missing Developer Stack of Taproot

Why Taproot still lacks the infrastructure developers need.

RootScope: A Tool for Reconstructing Taproot Script Paths — Step by Step

When you spend from a Taproot script path, the hash chain is deterministic. Reconstructing it by hand is a trap.

Commit-Reveal vs Dual-Layer Scripts: The Real Architecture of Bitcoin Script

The universal truth: Commit → Reveal and Single-Layer vs Dual-Layer Scripts.

Why V3 Matters: Bitcoin's Relay Layer Was Rewritten, and Most People Didn't Notice

V3, Package Relay, and Ephemeral Anchors quietly fixed a structural flaw in Bitcoin's fee and relay model.

The Anatomy of Bitcoin Scripts: From P2PKH to Taproot

Understanding these primitives is the foundation for everything that follows — Lightning, covenant proposals, and beyond.

Why Counterparty's Fake-Pubkey Grinding Reveals the Real Boundary Between Bitcoin Consensus and Policy

Consensus guarantees possibility. Policy guarantees sanity.

Bitcoin Doesn't Use Encryption — What Adam Back's Comment Really Means

Bitcoin has nothing encrypted. Its security is built on verification, not secrecy — and the real quantum risk is forgery, not decryption.

How Bitcoin P2SH Scripts Work: From 2-of-3 Multisig to Timelocked Inheritance

from Mastering Taproot — full chapter

Bitcoin Script Doesn't Execute What's on the Stack: A Developer's Journey From Misconception to Clarity

Not everything on the Bitcoin stack is meant to be executed — some things are meant to be verified, then forgotten.

Taproot Control Block Deep Analysis & Stack Execution Visualization | Part 2

In Part 1, we implemented a complete 4-leaf Taproot tree. Now we open the control block and visualize the stack.

Building a 4-Leaf Taproot Tree in Python: The First Complete Implementation on Bitcoin Testnet

Not Just HODLing #3 — a complete Taproot tree with five spending paths in Python and live-tested

How I Built a Time-Locked Bitcoin Script with CSV and P2SH

Not Just HODLing: Real Bitcoin Script Engineering #1

A Guide to Creating Taproot Scripts with Python Bitcoinutils

Not Just HODLing: Real Bitcoin Script Engineering #2

Bitcoin Inquisition 29.2 (opcode experiment index)

Inquisition 29.2 (on Core 29.3rc2) heretically activates BIP 118 (ANYPREVOUT), BIP 119 (CTV), BIP 347 (OP_CAT) and BIP 348 (CSFS) on signet — the opcode playground these experiments run on.

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CTV+CSFS: Can We Reach Consensus on a First Step Towards Covenants

The long-running debate on whether CTV+CSFS is the right first covenant step — including whether it is truly equivalent to APO / Lightning Symmetry; Aaron participated in the discussion.

Taproot-native prevout binding via sighash-preimage decomposition

Binding one input's outpoint to another using the sha_prevouts field of the sighash preimage as the anchor — full witness layout for the CTV+CSFS BitVM-bridge binding problem.

What exactly is bound in CSFS, IK+CSFS, and CHECKSIG?

An observable comparison of what three Tapscript constructions actually bind: CSFS binds a stack-supplied message (replayable), IK+CSFS binds identity, CHECKSIG binds the tx sighash (non-replayable).

Challenge: Covenants for Braidpool

Bob McElrath's open challenge to find covenant constructions for Braidpool's rolling coinbase aggregation (RCA → UHPO) custody; Aaron joined the thread with a reply.

Eltoo State Chain on Signet Again — 3 rounds, 2 tx (CSFS+CTV, rekey+ladder, no CAT)

Same three-round scenario, primitive switched to CSFS+CTV: a single CSFS delegation ladder with CTV-enforced settlement compresses the six transactions down to two — no OP_CAT.

Eltoo State Chain on Signet — 3 rounds, 6 tx (APO+CTV)

A three-round Eltoo-style state chain on Inquisition signet, each state UTXO a three-leaf Taproot tree (CTV settle, APO update, CSV escape) — six confirmed transactions.

CTV / APO / CAT Activity on Signet

AJ Towns' survey of how BIP 118 (APO), BIP 119 (CTV) and BIP 347 (OP_CAT) have actually been used on signet since 2022; Aaron participated in the thread.