Knowledge Base

Insights

Deep dives into Bitcoin security, self-custody strategies, and the evolving landscape of financial sovereignty.

A terminal window. gpg reports Good signature for the Sparrow manifest, and the hash check reports the Sparrow file OK.

October 13, 2026

Download and update Sparrow wallet the right way

Check your wallet app before you open it, in the terminal and not in the browser. Every step in plain words, the shorter steps for updates, and why we use gpg and not the checker inside Sparrow.

Two enlarged squares on one scale: the orange square of 10 million bitcoin key holders has half the area of the blue square of 20 million AI agent users.

October 12, 2026

Self-custody is rarer than AI agents

10 million people hold their own bitcoin keys. 20 million give AI agents real work. Both funnels drawn to scale, with multisig counted on our own node.

A grid of 100 squares: 65 blue, quantum secure, and 35 orange, public key on chain.

October 8, 2026

Most bitcoin is already quantum secure

64.6% of all bitcoin has never shown its public key, so a quantum computer has nothing to attack. Measured on our own node, with how to make the rest quantum secure.

Three signers and three backup plates on a dark table. Two signers show a gold check and the wallet card says 2 of 2 signatures: sent.

October 7, 2026

What is multisig?

A wallet that needs any 2 of 3 private keys to sign: what to keep, what you can lose, and why to test before you need it. With an 87 second film.

The long bitcoin address crossed out, with an arrow pointing to the name rob@bitsaga

October 6, 2026

Bitcoin Spaces

Own a name on Bitcoin itself, like rob@bitsaga, and let anyone pay it. How Spaces works, how it compares with BIP 353 and silent payments, and the proof on mainnet.

Two animations side by side showing one payment: on the left the proof goes on the chain inside a sealed envelope, on the right only a tiny marker goes on the chain

October 5, 2026

Two ways to shield Bitcoin

Two research papers, two opposite ideas: put the proof on the chain, or keep it off the chain. Watch the same payment travel through both.

Line chart of the hours of work needed to buy one ounce of gold, rising to about 117 hours in 2026

October 1, 2026

Hours of work to buy 1 ounce of gold

How many hours an average worker needs to work to buy one ounce of gold, from 500 BC to today, with the yearly inflation rate one click away.

Two envelopes side by side: on the left the sealed one the chain shows, 0 sat and 669 bytes of hex; on the right the same envelope opened with Bob's viewing key, showing 5,000 sat received

September 25, 2026

Shielded Bitcoin

Proof of concept: a shielded payment on Bitcoin mainnet, proving the mechanism on chain. Insecure by design, not usable today.

Two device screens side by side: stock SeedSigner magnifying one of 25 QR squares to copy by hand, and ShieldSigner confirming the secret was saved to a SeedKeeper card

September 17, 2026

Multisig on SeedSigner vs ShieldSigner

September 13, 2026

One Google search took down Silk Road

A simulated SeedSigner beside a wallet panel holding a 2-of-3 MuSig2 wallet, with three smartcards below

September 10, 2026

The future of multisig: airgapped MuSig2

Two SeedSigner screens: one reviewing a payment to a verified name, the other confirming the multisig signature

September 4, 2026

A 2-of-3 multisig that looks like one signature, paying a silent payment address

A helper server sending scanning data to a phone, with a chain of per-block fingerprints beneath it whose head is signed into a public record the server cannot edit

September 2, 2026

The silent payment server that can be caught lying

Coins under a day old are 78.9% of confirmed blocks but 4% of the pending mempool, while coins over a year old are 2.8% of blocks and 41.6% of the mempool

September 2, 2026

Most of the mempool is not competing with you

A short payment name on the left, and a SeedSigner approving a silent-payment spend on the right, with three different taproot outputs arriving from three payers

September 1, 2026

Silent payments on SeedSigner

Ninety-nine dice rolls feeding three firmware versions and splitting into three different wallets

August 27, 2026

Same dice, different wallet

A long bitcoin address beside a short payment name, the first marked as needing a fresh copy for every payer, the second as published once and never touched again

August 25, 2026

I replaced my bitcoin address with a name

A wallet on the left linked through three onion-routed relay hops to a stacked Bitcoin full node on the right, the path drawn as a shielded tunnel

August 24, 2026

Connect to the Bitsaga node

A grid of fine camera sensor noise on the left, the same grid flattened into smooth uniform blocks on the right, with the discarded fine detail marked in orange

August 22, 2026

The one number you cannot check

August 21, 2026

Bitcoin bottom on 3 November, says spiral chart

A histogram of bitcoin supply grouped by the euro price its holder paid, with a tall orange block in profit just below today's price and smaller blue-grey blocks underwater above it

August 21, 2026

The thinnest ceiling on record

An orange curve of remaining trust falling steeply with verification effort, approaching but never touching the dashed zero-trust line

August 20, 2026

The trust asymptote

The DIY Signing Device Revolution is Just Beginning

August 13, 2026

The DIY Signing Device Revolution is Just Beginning

Verifying SeedSigner

August 6, 2026

Verifying SeedSigner

Bitcoin at block resolution: 275 onchain metrics from our own archival node

August 6, 2026

Bitcoin at block resolution

Twenty-five things the chain says, each one measured on our own node

August 6, 2026

Twenty-five things the chain says

August 20, 2026

Nunchuk is 3,940 bytes from reproducible

Run the real SeedSigner firmware in your browser

August 3, 2026

Run the real SeedSigner firmware in your browser

Hardening a Linux agent server: 21 phases from first root login to a defensible box

August 2, 2026

Hardening a Linux agent server

Bitcoin's Graveyard: the fishbone chart of everything that died before Bitcoin

July 24, 2026

Bitcoin's Graveyard: the chart, and the branches that died

Bridges Burned: $35 Million Gone in Six Hours Proves Wrapped Bitcoin Is a Liability

July 23, 2026

Bridges Burned: $35 Million Gone in Six Hours Proves Wrapped Bitcoin Is a Liability

Dutch Court Exposes the Surveillance State's Bitcoin Honeypot

June 10, 2026

Dutch Court Exposes the Surveillance State's Bitcoin Honeypot

Dollar historically low, bitcoin ready to rocket

January 29, 2026

Dollar historically low, bitcoin ready to rocket

Why BIP 110's Size Limits Challenge Protocol Ossification

January 29, 2026

Why BIP 110's Size Limits Challenge Protocol Ossification

The AI – Bitcoin Energy Symbiosis

January 27, 2026

The AI – Bitcoin Energy Symbiosis

The Yen Carry unwind is bitcoin’s tailwind

January 27, 2026

The Yen Carry unwind is bitcoin’s tailwind

The Psychology of Diamond Hands

January 26, 2026

The Psychology of Diamond Hands

A Short Story About Inflation

January 15, 2026

A Short Story About Inflation

Bitcoin Core vs Knots

January 8, 2026

Bitcoin Core vs Knots

Seedsigner is the BTC Swiss army knife

July 17, 2025

Seedsigner is the BTC Swiss army knife

Bitcoin privacy

July 8, 2025

Bitcoin privacy

5 things Bitcoin is not

August 1, 2021

5 things Bitcoin is not