Latest reviewed change
source content difference between and
The entropy FAQ answer was rewritten, replacing the description of the TRNG/PRNG mix and SHA-256 whitening with revised wording that adds a note that hash conditioning is not a substitute for sufficient source entropy.
TRNG (True Random Number Generator), inside the main chip. This is
a dedicated hardware subsystem that measures analog noise produced
by a special transistor.
-The TRNG from the MCU would be sufficient, but we also maintain a
-PRNG which is mixed (by XOR) into the TRNG output. That PRNG is
-seeded once at boot up from the TRNG in each of SE1 and SE2. We
-limit the of use the TRNG present in the secure elements because
-the protocol involved is complex and slow.
First lines only. The complete diff is in the timeline below.
- Organisation
- Coinkite
- Evidence role
- Vendor documentation
- Published
- not established
- Source changes
- 3
- Detected differences
- 4
- Unreviewed
- 0
- Copies held
- 5
The pre-incident entropy description: hardware TRNG from transistor noise, a PRNG XOR'd into it, SE1/SE2 boot seeding, SHA-256 whitening, and the line that dice add "to the 256 bits of entropy already picked". Quoted on /how-it-broke/ to compare stated design against what shipped. It is monitored closely because it describes the affected subsystem. The first capture is post-disclosure and does not establish the page's earlier wording.
Every check is recorded, including checks that found no text change. A detected edit is therefore bounded between two checks. The publisher's exact save time is not observable from this record. Last checked .
This post is held twice: here, with this project's own note on why it matters, and again as part of the conversation captured at , which is polled for changes. Both copies are the same post; neither is a separate event.
Snapshot and diff bodies for this chain monitor are held in the local evidence archive but withheld from the public site because they can contain the addresses of people who published nothing themselves. Capture times and reviewed change summaries remain available below.
Held captures
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The entropy FAQ answer was rewritten, replacing the description of the TRNG/PRNG mix and SHA-256 whitening with revised wording that adds a note that hash conditioning is not a substitute for sufficient source entropy.
Recovered from the Internet Archive rather than captured by this project. The row records that third-party provenance separately from captures made by this project.
What changed from the previous capture 18 lines
TRNG (True Random Number Generator), inside the main chip. This is a dedicated hardware subsystem that measures analog noise produced by a special transistor. -The TRNG from the MCU would be sufficient, but we also maintain a -PRNG which is mixed (by XOR) into the TRNG output. That PRNG is -seeded once at boot up from the TRNG in each of SE1 and SE2. We -limit the of use the TRNG present in the secure elements because -the protocol involved is complex and slow. -The 256-bit number from the TRNG⊕PRNG is then "whitened" to remove -bias, by running it through SHA256. This means if your attacker was -somehow able to make the bits be 10% ones and 90% zeros (but still -random otherwise) it would not help them, because after SHA256 the -bit distribution will be 50/50 again. +The MCU TRNG output is mixed (by XOR) with output from a PRNG. That +PRNG is seeded once at boot from entropy obtained from SE1 and SE2. +The secure-element entropy is used for seeding rather than for every +request because the protocol is more complex and slower. +The 256-bit mixed value is then conditioned with SHA-256 before it is +used by the seed-generation workflow. Hash conditioning is not a +substitute for sufficient source entropy; it produces a deterministic +output from the input it receives. During seed picking process, you have the option of "adding dice rolls" to increase the entropy and/or mitigate any possible manipulation. You can add as many rolls as you wish, and the entropy (about 2.5Extracted text as captured
Skip to content COLDCARD Documentation COLDCARD FAQ Initializing search Documentation COLDCARD Home Buy Now! COLDCARD Documentation Documentation Documentation Guides Guides Getting Started Getting Started Quickstart! Start Here! Q Quickstart Guide Guide For Bitcoin Beginners PINs Master Seed Ready To Sign? Sending and Receiving Bitcoin for Beginners COLDCARD Ultra Quick Guide COLDCARD Middle Ground Guide COLDCARD Paranoid Guide General General Upgrade Firmware Settings Menu Address Explorer Verify Address Ownership QR Scanner Encrypted Backups NFC Tools Secure Notes & Passwords Multisig Features Airgap Multisig Seed Management Seed Management Generate Seed Generate SeedExcerpt only. The complete copy is held offline and backs quotations on this site. The original publication remains the canonical public source.
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The FAQ changed one migration-guide link text from Check firmware and migration steps to Open the step-by-step migration guide.
Recovered from the Internet Archive rather than captured by this project. The row records that third-party provenance separately from captures made by this project.
What changed from the previous capture 2 lines
Where do I learn all technical details? COLDCARD Security Advisory A seed-generation defect affected releases beginning with firmware 4.0.1. Fixed firmware is available. Existing affected seeds still require migration. -Check firmware and migration steps +Open the step-by-step migration guide Home Docs COLDCARD FAQExtracted text as captured
Skip to content COLDCARD Documentation COLDCARD FAQ Initializing search Documentation COLDCARD Home Buy Now! COLDCARD Documentation Documentation Documentation Guides Guides Getting Started Getting Started Quickstart! Start Here! Q Quickstart Guide Guide For Bitcoin Beginners PINs Master Seed Ready To Sign? Sending and Receiving Bitcoin for Beginners COLDCARD Ultra Quick Guide COLDCARD Middle Ground Guide COLDCARD Paranoid Guide General General Upgrade Firmware Settings Menu Address Explorer Verify Address Ownership QR Scanner Encrypted Backups NFC Tools Secure Notes & Passwords Multisig Features Airgap Multisig Seed Management Seed Management Generate Seed Generate SeedExcerpt only. The complete copy is held offline and backs quotations on this site. The original publication remains the canonical public source.
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The FAQ page added a security advisory banner stating a seed-generation defect affected firmware 4.0.1 onward, that fixed firmware is available, and that affected seeds still require migration.
Recovered from the Internet Archive rather than captured by this project. The row records that third-party provenance separately from captures made by this project.
What changed from the previous capture 3 lines
What happens when I can't remember my PIN? Where does the entropy (randomness) come from? Where do I learn all technical details? +COLDCARD Security Advisory +A seed-generation defect affected releases beginning with firmware 4.0.1. Fixed firmware is available. Existing affected seeds still require migration. +Check firmware and migration steps Home Docs COLDCARD FAQExtracted text as captured
Skip to content COLDCARD Documentation COLDCARD FAQ Initializing search Documentation COLDCARD Home Buy Now! COLDCARD Documentation Documentation Documentation Guides Guides Getting Started Getting Started Quickstart! Start Here! Q Quickstart Guide Guide For Bitcoin Beginners PINs Master Seed Ready To Sign? Sending and Receiving Bitcoin for Beginners COLDCARD Ultra Quick Guide COLDCARD Middle Ground Guide COLDCARD Paranoid Guide General General Upgrade Firmware Settings Menu Address Explorer Verify Address Ownership QR Scanner Encrypted Backups NFC Tools Secure Notes & Passwords Multisig Features Airgap Multisig Seed Management Seed Management Generate Seed Generate SeedExcerpt only. The complete copy is held offline and backs quotations on this site. The original publication remains the canonical public source.
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Recovered from the Internet Archive rather than captured by this project. The row records that third-party provenance separately from captures made by this project.
What changed from the previous capture 0 lines
Extracted text as captured
Skip to content COLDCARD Documentation COLDCARD FAQ Initializing search Documentation COLDCARD Home Buy Now! COLDCARD Documentation Documentation Documentation Guides Guides Getting Started Getting Started Quickstart! Start Here! Q Quickstart Guide Guide For Bitcoin Beginners PINs Master Seed Ready To Sign? Sending and Receiving Bitcoin for Beginners COLDCARD Ultra Quick Guide COLDCARD Middle Ground Guide COLDCARD Paranoid Guide General General Upgrade Firmware Settings Menu Address Explorer Verify Address Ownership QR Scanner Encrypted Backups NFC Tools Secure Notes & Passwords Multisig Features Airgap Multisig Seed Management Seed Management Generate Seed Generate SeedExcerpt only. The complete copy is held offline and backs quotations on this site. The original publication remains the canonical public source.
1 presentation-noise difference. Sidebar, ticker and other page chrome churn that our review classified as not being a change to what the source says.
- +1 -1 Only the FAQ footer's Last update date changed from July 31 to August 1; no extracted FAQ answer changed.
The excerpts and plain unified diffs above show the text this project held and how it changed. To verify a quotation, compare it against the page itself or against the Internet Archive's copies, which are independent of this project.
Complete captures are held offline rather than mirrored here, so this page shows diffs and excerpts. If a quotation is ever disputed, the full copy can be produced. Ask.
Compare the screenshot or a quotation against the original while it is available.