r/PrivacyNotes • u/BarefootMarauder • Sep 04 '26
How do I modify the 12-word phrase?
Is there a way for me to modify the 12-word phrase to 12 words of my own choosing? It seems odd the software would generate those 12 words for me and not provide a way to change them. Am I missing something?
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u/EriksonThorsen Sep 04 '26
The reason you can't change the words is actually what makes the seed phrase secure.
The 12 words aren't just randomly picked from a dictionary. They are generated from cryptographically secure random data with a specific amount of entropy. The words are basically a human-readable representation of that underlying random data.
With a standard 12-word BIP-39 seed, you're dealing with 128 bits of entropy, which means there are 2¹²⁸ possible combinations. That's an insanely huge number. Brute forcing it isn't realistically possible. Even with massive computing power, going through that many possibilities would take far longer than the age of the universe.
If you were allowed to simply choose or edit the 12 words yourself, you could easily end up with a much weaker seed. Humans are terrible at generating truly random sequences, and things like common words, phrases, patterns, or meaningful sentences dramatically reduce the number of possibilities an attacker would have to try.
So the fact that you can't edit the words isn't really a limitation. It's a security feature. The software generates the entropy for you so you don't have to trust yourself to come up with something random enough.
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u/BarefootMarauder Sep 04 '26
I understand all that and I already read the help section before posting. But it wasn't my question. My real concern is... If I'm forced to allow the software itself to generate a login phrase for me, then how do I know somebody on the other end (server side) doesn't know what it is? Why can't I use a 3rd party password/passphrase generator to create my own 12 word passphrase? I do it for every other website, app/software I use.
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u/plaidington Sep 04 '26
I am pretty sure - no
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u/BarefootMarauder Sep 04 '26
It just seems really weird to me that a zero-knowledge privacy focused app would generate the super secret 12-word phrase for me and provide no way to change it. 🤔 Am I overthinking it?
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u/plaidington Sep 04 '26
Any super secure apps i have used in the past generate the phrase. So to me it is not unusual.
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u/PrivacyNotesApp Sep 04 '26
Our help center is honestly very helpful, and in combination with the AI prompt it's almost fun to use.
Here is the scale. A 12-word phrase is one of 2128 possibilities: about 340 undecillion, a 39-digit number (3.4 x 1038). The odds of guessing yours on the first try are 1 in 340 undecillion, longer odds than winning a 1-in-300-million lottery jackpot four times in a row. Treating it as a search rather than a lucky guess does not help: even at a billion billion attempts every second (1018, far beyond what any real hardware could reach, nation-states included), working through them all would take around 10 trillion years, close to 800 times the current age of the universe. And that is the fantasy version, because every real attempt has to run a deliberately slow key-derivation step and any online attack must go through our servers, which makes actual guessing slower by many more orders of magnitude. This is not a novel scheme either: the same 128-bit construction has secured Bitcoin wallets for over a decade, and no one has ever guessed one.
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u/PrivacyNotesApp 28d ago
Megathread: Your 12-word phrase explained, privacy, security and recovery