r/coldcard: owner asking what the entropy issue means
reddit-entropy-explainer-question
https://www.reddit.com/r/coldcard/comments/1vf4hdx/is_it_only_about_entropy_i_dont_get_it/
Latest reviewed change
source content difference between and
The thread gained a comment stating that COLDCARD used a pseudo-random number generator, so the seed phrases were not truly random.
By any chance do you know if CC way of converting this, is the same used by other tools? Like SeedSigner, Sparrow Wallet's dice input, and Ian Coleman's BIP39?
Meaning that if you put the same numbers in such tools you will get exactly the same seed and in the CC wallet.
+comment: p29v91k
+parent: t3_1vf4hdx
+author: Full-Guide-7713
+created_utc: 1786113419
+edited: false
First lines only. The complete diff is in the timeline below.
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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 thread gained a comment stating that COLDCARD used a pseudo-random number generator, so the seed phrases were not truly random.
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 8 lines
By any chance do you know if CC way of converting this, is the same used by other tools? Like SeedSigner, Sparrow Wallet's dice input, and Ian Coleman's BIP39? Meaning that if you put the same numbers in such tools you will get exactly the same seed and in the CC wallet. +comment: p29v91k +parent: t3_1vf4hdx +author: Full-Guide-7713 +created_utc: 1786113419 +edited: false +body: +The coldcard was using a pseudo random number generator which is basically an algorithm to generate the seed phrases. Hence, they were not truly random. + more-stub: parent t1_p1nmdos count <live-count>Extracted text as captured
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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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A commenter asked whether COLDCARD’s number-to-seed conversion is compatible with SeedSigner, Sparrow and Ian Coleman tools.
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 11 lines
That is still secure enough, unlike 40 bits as was the case with the coldcard flaw +comment: p1xzxe6 +parent: t1_p1n60hq +author: JumpProfessional3372 +created_utc: 1785967283 +edited: false +body: +>So the wallet doesn't pick random words but just a single number and translates that number into words for you to write down safely without messing up zeroes and ones. + +By any chance do you know if CC way of converting this, is the same used by other tools? Like SeedSigner, Sparrow Wallet's dice input, and Ian Coleman's BIP39? +Meaning that if you put the same numbers in such tools you will get exactly the same seed and in the CC wallet. + more-stub: parent t1_p1nmdos count <live-count>Extracted text as captured
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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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A comment was edited to change its stated entropy figure for 23 randomly chosen words from 230 to 253 bits, and its illustrative reduced figure from 150 to 200 bits.
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 8 lines
parent: t3_1vf4hdx author: Ok-Pea4148 created_utc: 1785905295 -edited: false -body: -If they are chosen truly randomly, 23 words give you 230 bits of entropy. But human brains -are poor random number generator, so instead of 230 bits, you might only get say 150 bits. +edited: 1785921310 +body: +If they are chosen truly randomly, 23 words give you 253 bits of entropy. But human brains +are poor random number generator, so instead of 253 bits, you might only get say 200 bits. That is still secure enough, unlike 40 bits as was the case with the coldcard flawExtracted text as captured
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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 thread gained a comment estimating entropy from randomly chosen words and contrasting it with the commenter's stated estimate for the flaw.
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 11 lines
Watch this video to answer your question: [https://x.com/TFTC21/status/2084342383274283023/video/1?s=46](https://x.com/TFTC21/status/2084342383274283023/video/1?s=46) +comment: p1sm79v +parent: t3_1vf4hdx +author: Ok-Pea4148 +created_utc: 1785905295 +edited: false +body: +If they are chosen truly randomly, 23 words give you 230 bits of entropy. But human brains +are poor random number generator, so instead of 230 bits, you might only get say 150 bits. + +That is still secure enough, unlike 40 bits as was the case with the coldcard flaw + more-stub: parent t1_p1nmdos count <live-count>Extracted text as captured
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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 Reddit thread gained new participant comments.
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 12 lines
body: The random number generator essentially only ever produced a subset of those seed phrases. Attacker knows the subset and tries them all with lots of computing power +comment: p1qy26b +parent: t3_1vf4hdx +author: blurred_rabbit +created_utc: 1785884716 +edited: 1785885257 +body: +I’m pretty sure the code’s fallback path that was used had a few pre-determined variables (such as date/time and a few other things) that went into generating the seeds to make the hackers job a little bit easier. + +In addition to the core issue of the entropy not being nearly enough for modern day computers (estimated 1-3 hours to brute force the level of entropy). + +Watch this video to answer your question: [https://x.com/TFTC21/status/2084342383274283023/video/1?s=46](https://x.com/TFTC21/status/2084342383274283023/video/1?s=46) + more-stub: parent t1_p1nmdos count 0Extracted text as captured
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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
post: 1vf4hdx author: Psychological-Hawk80 created_utc: 1785832374 title: Is it only about entropy? I don't get it. body: I don't get it. Is it all about bad entropy? If I choose by myself without any dice 24 word from Bip39 (ok 23 and do the calculation for the 24th) then it shoul be a rather good seed and nobody will be able to "crack" it just by bruteforce? There must something else in the recent incidence which allows hacker at least to predict some of the generated seeds especially in MK3 devices? Can somebody please explain it to me ? Was only a subset of the bip39 words choosen by the algorithm? comment: p1m2suw parent: t3_1vf4hdx author: megagram created_utc: 1785833094 edited: false body: To dumb it down… think about having a million cups on a table facing down. Under one of those cups a gold piece is randomly placed. In true randomness it would be next to impossible for you to correctly choose which cup had the gold ball. However if you knew the person placing the gold piece only ever chose to place the piece in one of three cups your chances of selecting the cup with the gold would be much higher. That is the difference between good entropy and bad. What happened with coldcard was instead of truly randomly choosing one of the million cups, it only chose 100. Attackers figured this out and stayed peeking under those 100 cups. comment: p1m34mj parent: t3_1vf4hdx author: Interesting-Gear-992 created_utc: 1785833259 edited: false body: https://youtu.be/IwrKWdxt0YM?is=fT9JuJc4bn8bdMIZ comment: p1m6stt parent: t1_p1m34mj author: Psychological-Hawk80 created_utc: 1785835076 edited: false body: Thanks - a very good explanation. It is about prediction and a limmited set of possible generated seeds. As soon as the weakness was revealed, should not have some good guys or Coldcard itself tried to transfer BTC from the affected seeds to save it at a good place for affected customers? In order to compete witht the bad guys? comment: p1m7gkf parent: t1_p1m6stt author: Interesting-Gear-992Excerpt 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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