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r/Bitcoin: whether a 10-character passphrase is enough after the Coldcard incident

reddit-passphrase-entropy-ten-char

https://www.reddit.com/r/Bitcoin/comments/1vhux2b/is_my_understanding_of_the_security_of_a_25th/

Latest reviewed change

source content difference between and

Reddit served 2 additional comment record(s); the diff preserves their text and any edits to existing records.

seen +18 -0 full history below
 edited: false
 body:
 Checkout this site for good info on this. [https://drop.amboss.tech/entropy-explainer.html](https://drop.amboss.tech/entropy-explainer.html)
+
+comment: p2n9p1e
+parent: t1_p2bwmui
+author: Londonskaterboi
+created_utc: 1786283480

First lines only. The complete diff is in the timeline below.

Organisation
reddit
Evidence role
Community discussion
Published
not established
Source changes
1
Detected differences
1
Unreviewed
0
Copies held
2

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 .

  1. source content difference between and Current source content +18 -0

    Reddit served 2 additional comment record(s); the diff preserves their text and any edits to existing records.

    seen · Captured here 5,765 chars
    What changed from the previous capture 18 lines
     edited: false
     body:
     Checkout this site for good info on this. [https://drop.amboss.tech/entropy-explainer.html](https://drop.amboss.tech/entropy-explainer.html)
    +
    +comment: p2n9p1e
    +parent: t1_p2bwmui
    +author: Londonskaterboi
    +created_utc: 1786283480
    +edited: false
    +body:
    +yes but some wallets only accept bip39 words
    +
    +comment: p2ncvz8
    +parent: t1_p2n9p1e
    +author: na3than
    +created_utc: 1786284458
    +edited: false
    +body:
    +1. Picking "four words that are easy to remember" from a list of only 2048 words is absolutely not random.
    +
    +2. Every wallet that accepts a passphrase accepts any combination of letters, numbers and special characters as a passphrase. That's what a passphrase is. Check the specification. It's NOT meant to be a few more words from the canonical list of 2048. If you've found a wallet that stupidly constrains your passphrase that way, stop using that shitty wallet. There's no telling what other dumb decisions the authors made is implementing the specifications.
    
    Extracted text as captured
    post: 1vhux2b
    author: Maleficent_Pool_4456
    created_utc: 1786091663
    title: Is my understanding of the security of a 25th word Passphrase correct?
    body:
    So the number of different characters you can use ASCII etc for things like Ledger is 94, so the base (number of possible things for each character) would be 94 and the exponent would be the length right, so let's say if you had 10 characters, a strong hacker who is check 10million per second (including the 2048 rounds of hashing) it would take them 85,000 years, and would take like a nation state with a lot of funds checking 1 billion per second 853 years.
    
    Does this mean, that if you have a random password of 10 characters for your 25th password, that you would have 59 bits of entropy, therefore you are relatively safe even if they had your first 24?
    
    Of course keep your first 24 hidden, but I'm asking in a case like ColdCard, you would be safe right and **10 characters is enough?**
    
    comment: p2889x7
    parent: t3_1vhux2b
    author: Pleasant_Tap2641
    created_utc: 1786092230
    edited: false
    body:
    So you're basically asking if 10 random chars is enough to sleep at night even if someone swipes your seed words
    
      
    short answer yeah probably but the real question is why stop at 10 when you can just mash the keyboard a few more times and call it a day
    
    comment: p288dcc
    parent: t3_1vhux2b
    author: ivanjurman
    created_utc: 1786092275
    edited: false
    body:
    Yes you’re correct, but if you want to be extra safe just by increasing the length to 20 characters, it would take them 10 septillion years (thats 10 trillion trillion years)
    
    comment: p288ymj
    parent: t3_1vhux2b
    author: Londonskaterboi
    created_utc: 1786092563
    edited: false
    body:
    you can add multiple words like the actual seed phrase, so pick 4 words that are easy to remember but have no real life connection.
    
    comment: p2896as
    parent: t3_1vhux2b

    Excerpt only. The complete copy is held offline and backs quotations on this site. The original publication remains the canonical public source.

  2. Earliest copy held
    seen · Captured here 4,954 chars
    Extracted text as captured
    post: 1vhux2b
    author: Maleficent_Pool_4456
    created_utc: 1786091663
    title: Is my understanding of the security of a 25th word Passphrase correct?
    body:
    So the number of different characters you can use ASCII etc for things like Ledger is 94, so the base (number of possible things for each character) would be 94 and the exponent would be the length right, so let's say if you had 10 characters, a strong hacker who is check 10million per second (including the 2048 rounds of hashing) it would take them 85,000 years, and would take like a nation state with a lot of funds checking 1 billion per second 853 years.
    
    Does this mean, that if you have a random password of 10 characters for your 25th password, that you would have 59 bits of entropy, therefore you are relatively safe even if they had your first 24?
    
    Of course keep your first 24 hidden, but I'm asking in a case like ColdCard, you would be safe right and **10 characters is enough?**
    
    comment: p2889x7
    parent: t3_1vhux2b
    author: Pleasant_Tap2641
    created_utc: 1786092230
    edited: false
    body:
    So you're basically asking if 10 random chars is enough to sleep at night even if someone swipes your seed words
    
      
    short answer yeah probably but the real question is why stop at 10 when you can just mash the keyboard a few more times and call it a day
    
    comment: p288dcc
    parent: t3_1vhux2b
    author: ivanjurman
    created_utc: 1786092275
    edited: false
    body:
    Yes you’re correct, but if you want to be extra safe just by increasing the length to 20 characters, it would take them 10 septillion years (thats 10 trillion trillion years)
    
    comment: p288ymj
    parent: t3_1vhux2b
    author: Londonskaterboi
    created_utc: 1786092563
    edited: false
    body:
    you can add multiple words like the actual seed phrase, so pick 4 words that are easy to remember but have no real life connection.
    
    comment: p2896as
    parent: t3_1vhux2b

    Excerpt 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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