generating seed phrases offline and which wallets support custom passprhases?

dkbit98

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Quote from: acme89 on May 04, 2024, 01:10:50 PM

How could I safely generate custom seed phrases offline, and which tools are good for this operation?

Easiest way to do this is by using airgapped hardware wallets since they already support Bitcoins and most of available altcoins.
I would only use devices with open source code, something like Keystone would probably work best in your case.
If you don't want to pay for hardware wallets than you just need offline laptop with clean Linux OS, or reset old smartphone (best with GrapheneOS or DivestOS) in airplane mode, with wifi and bluetooth disabled.
Note that newbies should be very careful doing anything they don't fully understand.

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Quote from: acme89 on May 04, 2024, 01:10:50 PM

Hi. I have two questions.

How could I safely generate custom seed phrases offline, and which tools are good for this operation?

And I need wallets for other networks, not just for BTC.

If you need a bunch of SEEDs for other networks wallets I would advocate the use of BIP85 child seeds generated from the single master SEED.

You may use for this purpose Tails OS with persistent volume enabled.

Copy into persistent volume the latest release of the stand-alone script (bip39-standalone.html) to generate master SEED and relevant child ones.

Run it , and shazam!

Quote from: acme89 on May 04, 2024, 01:10:50 PM

What software supports generating seed phrases with custom passphrases, and in which software wallets such phrases could be imported?

Most of them do this.

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Quote from: acme89 on May 04, 2024, 01:10:50 PM

How could I safely generate custom seed phrases offline, and which tools are good for this operation?

It's offline so it should be relatively safe compared to generating it online as long as the software's entropy sources aren't rigged.
If you do not have the means to review the software's code, stick to the famous well-reviewed wallets.

To be even more secure, pick an OS that has good RNG since the wallet software will be using it.
Most OS has good pRNG but only those "open-source" that you can audit.
Of course, the hardware as well but can anyone even verify its integrity without personally building each component?

But generally, keeping the wallet on an "air-gap" machine should be safe enough.
Generating the seed phrase offline, then using the created wallet online will just defeat that question's purpose.

Quote from: acme89

What software supports generating seed phrases with custom passphrases, and in which software wallets such phrases could be imported?

There are a lot of good Bitcoin-exclusive wallets and almost all supports "BIP39 passphrase".
Unfortunately, for multi-coin wallet, it's hard to give recommendation to any.

NeuroticFish

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Quote from: acme89 on May 04, 2024, 01:10:50 PM

Hi. I have two questions.

How could I safely generate custom seed phrases offline, and which tools are good for this operation?

What software supports generating seed phrases with custom passphrases, and in which software wallets such phrases could be imported?

One of the best methods I was told of was the one that uses /dev/urandom and a copy of Ian Coleman's tool on an offline Linux machine:
https://bitcointalksearch.org/topic/m.63228430
This returns standard BIP39 seed and all proper wallets that work with seed will accept it.

Another, much easier method is to create a new seed with Electrum wallet. But this will work only on Electrum.
On the other hand, Sparrow wallet creates BIP39 seed, but it's not as widely available as Electrum or the first method I've linked.

Flipping a coin or rolling a dice is also a method, but you better search on the forum because it seems it's pretty easy to do it wrong.

Of course, hardware wallets also generate BIP39 standard seed, but some of them have lately... trust issues.

PS. Ian Coleman's tool also does this, but afaik in-browser random generator is not considered good enough for the job. That's why method 1 uses /dev/urandom separately.

acme89

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Hi. I have two questions.

How could I safely generate custom seed phrases offline, and which tools are good for this operation?

What software supports generating seed phrases with custom passphrases, and in which software wallets such phrases could be imported?

And I need wallets for other networks, not just for BTC.

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