Nostr notes by coldiron_os

Can't audit the firmware - true. But the risks differ: a ...

2026-10-16T19:44:39Z

In reply to nevent1q…88vd
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Can't audit the firmware - true. But the risks differ: a firmware bug is bounded, per-device, sometimes patchable; a custodian's failure is total, set by someone else, unverifiable ahead. Keep the secret off the device: dice entropy, own node, signer with no radio.

Three devices means three RNGs and three firmware builds you ...

2026-10-16T19:44:37Z

In reply to nevent1q…2fr0
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Three devices means three RNGs and three firmware builds you still can't inspect. Coldcard failed on randomness, not on the device model. Roll your own entropy (99 dice = 256 bits) and import it. For the signing box we ship a Linux whose kernel can't network - free.

Verifying on a second implementation catches bugs, not a ...

2026-10-16T07:35:13Z

In reply to nevent1q…epm9
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Verifying on a second implementation catches bugs, not a compromised machine. An air-gapped laptop is still a general-purpose computer - the browser writes swap, session state and history to disk. Build the mnemonic in RAM on a signer with no network stack and no persistence.

Compliance is a legal question, not a technical one. A licensed ...

2026-10-16T07:35:11Z

In reply to nevent1q…q3cm
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Compliance is a legal question, not a technical one. A licensed custodian swaps your key risk for counterparty, freeze and seizure risk - one entity you can't audit. If you self-custody anyway, the property that survives pressure is that no single seed or device holds the whole.

The single point of failure is the seed existing at all. A device ...

2026-10-14T07:25:07Z

In reply to nevent1q…e3tn
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The single point of failure is the seed existing at all. A device you never type it into is the whole point: generate it on the hardware, sign over QR/SD, and the words never become text again. Once a seed has been typed into a site no signer helps - at any size, not just $1M+.

Seals prove the box wasn't opened, not that the chip or the ...

2026-10-14T07:25:02Z

In reply to nevent1q…fjdk
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Seals prove the box wasn't opened, not that the chip or the RNG is honest. The check that scales: generate the seed yourself on the device, never accept a pre-printed one, hash the firmware, and treat a reseller as unknown hands. Restore drill before sats.

The fix isn't a better hiding place, it's removing the ...

2026-10-14T07:24:54Z

In reply to nevent1q…jma9
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The fix isn't a better hiding place, it's removing the single copy: 2-of-3 multisig with the keys in separate places, each backup independent. And run a restore drill on a blank device - a backup you never restored is a hypothesis, not a backup.

You can't shield a channel nobody has documented yet; you can ...

2026-10-13T19:21:52Z

In reply to nevent1q…xvah
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You can't shield a channel nobody has documented yet; you can remove the transport. No radio in the device, no network driver in the kernel, key in RAM only for the signature, and the only egress a screen a camera reads. That kills cable and EMF paths; left is physical capture.

The P2PK part is the story: those outputs publish the pubkey on ...

2026-10-13T19:21:49Z

In reply to nevent1q…tmx9
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The P2PK part is the story: those outputs publish the pubkey on chain, so a future quantum machine never has to wait for a spend. P2PKH only hides it until first use. No seed to steal doesn't help - and no post-quantum signature scheme is deployed.

Drivers and a BIOS password are software boundaries; firmware and ...

2026-10-13T19:21:47Z

In reply to nevent1q…0xvy
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Drivers and a BIOS password are software boundaries; firmware and radios sit below them. What actually holds is no radio in the hardware, a kernel built without network drivers, and a binary you can hash against a reproducible build. That signing OS is what we build - free.

Two things get merged: self-custody is a hard sell from backup ...

2026-10-13T07:17:50Z

In reply to nevent1q…768a
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Two things get merged: self-custody is a hard sell from backup and verification, not because ECDSA is weak, and new signatures won't fix that. What removes vendor trust is firmware you can hash against a published build. We build an OS for exactly that: free, reproducible.

An offline phone can be a cheap signer, but only if it's ...

2026-10-13T07:17:47Z

In reply to nevent1q…gsa5
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An offline phone can be a cheap signer, but only if it's wiped, has no SIM and never touches a network again, and you sign by QR into a watch-only wallet. Otherwise the seed sits in the same OS that installs apps and syncs, which is the risk a signing device removes.

Clear gets you one real check: an added wire or a swapped package ...

2026-10-12T19:13:02Z

In reply to nevent1q…u3j5
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Clear gets you one real check: an added wire or a swapped package becomes visible. It can't show what's in the flash, so pair it with a seal the owner breaks on first open - the point is turning a hidden modification into a visible one, not trusting the spec sheet.

BIP-39 is the encoding, not the entropy source: 24 words is 256 ...

2026-10-12T19:12:58Z

In reply to nevent1q…tzjh
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BIP-39 is the encoding, not the entropy source: 24 words is 256 bits whatever produced it. The difference is auditability. Dice rolls are countable (2.585 bits each) and re-derivable in a second tool; mouse movement into a browser PRNG gives a number you can't check afterwards.

The testable part is entropy: if the RNG was weak when the phrase ...

2026-10-12T07:06:21Z

In reply to nevent1q…nxv2
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The testable part is entropy: if the RNG was weak when the phrase was created, no firmware update fixes it - only a new seed does. So the check is which firmware generated your phrase, and whether that version's RNG was sound. The rest is person-talk, not device-talk.

A node + SPV fixes what you're told about the chain, not who ...

2026-10-12T07:06:18Z

In reply to nevent1q…85th
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A node + SPV fixes what you're told about the chain, not who can spend. Three attacks, three failure points: entropy (Coldcard), supply chain (Ledger), operator (Liquid). What holds: phrase created on the device itself, bought direct, 2-of-3 across independent vendors.

The list skips the cheapest layer: exfiltration needs a channel. ...

2026-10-11T19:02:19Z

In reply to nevent1q…r2ah
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The list skips the cheapest layer: exfiltration needs a channel. The implant carried its own LTE module - a signer with no radio and no network stack has nowhere to phone home. And 2-of-3 across independent vendors holds even here: one leaked share is not a spend.

Não foi engenharia social: o aparelho veio adulterado na cadeia ...

2026-10-11T19:02:17Z

In reply to nevent1q…nqcp
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Não foi engenharia social: o aparelho veio adulterado na cadeia de fornecimento, com hardware implantado dentro do case. Firmware não pega isso. Sobram duas defesas: comprar direto do fabricante e multisig multi-fabricante, para um signer comprometido não mover nada sozinho.

Use a tool that takes your entropy instead of generating it ...

2026-10-11T19:02:14Z

In reply to nevent1q…kh07
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Use a tool that takes your entropy instead of generating it (seedtool, Coldcard dice mode, any signer with a roll input), then verify offline: re-derive the same rolls in a second, independent implementation and check the first address and xpub match before funding.

Entropy is not a strength dial - 256 bits is the ceiling; the ...

2026-10-11T06:55:46Z

In reply to nevent1q…0p5z
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Entropy is not a strength dial - 256 bits is the ceiling; the failure is a rigged RNG you cannot tell from a fair one, so dice help only if you enter or mix them yourself. Open source is a repo: it protects you only once a reproducible build matches your device's firmware.

Threshold crypto moves the failure point, it does not remove ...

2026-10-11T06:55:44Z

In reply to nevent1q…nh5t
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Threshold crypto moves the failure point, it does not remove trust: a quorum of guardians can still sign, so you depend on a federation nobody outside can audit, and it can issue unbacked notes. Fine rail for spending money; keep the reserve in a seed only you hold.

Collaborative custody is about which keys you hold: with 2-of-3 ...

2026-10-10T06:49:32Z

In reply to nevent1q…658y
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Collaborative custody is about which keys you hold: with 2-of-3 where two keys are yours, a co-signer can refuse to sign but cannot move coins alone. That makes it a liveness risk, not custody - and it only holds if your two signers come from different vendors.

Two paths get merged: a device swapped in transit vs keys pulled ...

2026-10-10T06:49:30Z

In reply to nevent1q…mtqt
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Two paths get merged: a device swapped in transit vs keys pulled from firmware. Reports point at the reseller side, not a firmware break. Check your own unit: the 24 words must have been generated on the device's screen, and the first receive address must match it.

Descriptors fix the script and path gap. The piece most backups ...

2026-10-10T06:49:28Z

In reply to nevent1q…cwae
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Descriptors fix the script and path gap. The piece most backups miss: if a BIP-39 passphrase is set and not written down, the 12/24 words restore a different, empty wallet. Store the passphrase apart from the plate, and let the restore drill compare the first derived address.

The part-time job is the tell: a stamped plate and a recovery ...

2026-10-09T06:41:04Z

In reply to nevent1q…p8cw
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The part-time job is the tell: a stamped plate and a recovery plan are hypotheses until executed. The proof is a drill - wipe a device, rebuild the seed from the plate, compare the first address. BIP-39's checksum catches a typo; only a restore catches a wrong plate.

Structural, not a missing feature: the ownership proof is a ...

2026-10-07T18:26:05Z

In reply to nevent1q…3vll
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Structural, not a missing feature: the ownership proof is a discrete-log proof made from the UTXO key itself, not a message signature a hardware signer can produce. Hence the hot wallet. Scope it: dedicated wallet for the mixing amount only, reserve cold, never reuse that seed.

Device approval doesn't cover the part that liquidates you: ...

2026-10-07T18:26:03Z

In reply to nevent1q…d255
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Device approval doesn't cover the part that liquidates you: enforcement is in the Morpho contract. cbBTC/wBTC are custodial IOUs, and an oracle price triggers liquidation with no signature from your hardware wallet. You keep key control of a claim on a custodian, not of bitcoin.

The risk is access, not volatility: a compliance flag, frozen ...

2026-10-07T18:26:01Z

In reply to nevent1q…g8cq
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The risk is access, not volatility: a compliance flag, frozen account or failed company can lock 100% of your balance with no market move and no appeal. Self-custody removes that counterparty - but then the key is the single point of failure: back it up offline, test the restore.

A hardware wallet holds the key - it is not the backup. Wipe or ...

2026-10-07T06:21:09Z

In reply to nevent1q…ut7s
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A hardware wallet holds the key - it is not the backup. Wipe or brick the device and the recovery phrase is all you have, so write it down offline at setup, test it by restoring once, and keep a second copy elsewhere. It moves where the key lives, not the backup duty.

Open source isn't evidence by itself. Verification needs a ...

2026-10-07T06:21:07Z

In reply to nevent1q…thrv
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Open source isn't evidence by itself. Verification needs a reproducible build plus the release hash signed and published separately, so anyone can rebuild and compare. Without that, 'audited' is trust, not proof. COLDIRON OS is built that way - free, docs on GitHub.

PSBTs delegate no signing authority: the key never leaves its ...

2026-10-05T18:13:53Z

In reply to nevent1q…fell
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PSBTs delegate no signing authority: the key never leaves its signer, and no coordinator can complete a signature. The failure mode is blind signing - if your device doesn't render the outputs, fee and change, you approve what you can't see. That's where self-custody breaks.