A way to produce a deterministic brain wallet for temporary use while crossing borders without physical paper, devices, or need to memorize 12 or 24 seed words.
Find a URL that will be widely available for a time, will remain consistent, and is easy enough to remember
- for example: The twitter icon at https://twitter.com/favicon.ico And a pass phrase
- for this example, i'll use 'brainstorm'
August 2023 -- Twitter is owned by Elon Musk and he's rebranding it to X. As of early August 2023, the URI above still references the preferred favicon file, but this is likely going to change. This demonstrates why this kind of wallet should be fairly short lived. Don't choose a resource that is going through turmoil itself. You may want to consider choosing an image available on the Internet Wayback machine based on URL and date. For example: https://web.archive.org/web/20230601000430im_/https://abs.twimg.com/favicons/twitter.2.ico
Then you can use this set of commands on a linux system
# Set the path of the resource
COMMON_URL="https://gist.github.com/favicon.ico"
# Set the password
SECRET_PWD="brainstorm"
# Now run this to consistently produce the same set of seed words using
# the above resource and the password as input
cd /tmp
wget https://raw.githubusercontent.com/Coldcard/firmware/master/docs/rolls.py
echo `wget -qO- ${COMMON_URL} | xxd -p | tr -d '\n'` `echo ${SECRET_PWD}` | /usr/bin/env python3 rolls.py Using the above, the example output is shown below. You may want to test to verify you get the same results.
d3a5f8ade8d496ff4351d3d97b4f2c632c3f29285575c8f0a6c321a2f6f234b7
1: squirrel
2: cool
3: clock
4: spider
5: enact
6: leisure
7: ask
8: denial
9: sunny
10: surprise
11: slam
12: shock
13: sentence
14: nest
15: pattern
16: push
17: similar
18: lunch
19: radio
20: drive
21: control
22: jungle
23: spot
24: top
Obviously, you should pick your own COMMON_URL and SECRET_PWD value when using this
- The resulting seed words should be used in the wallet of your choice to determine a receive address.
- Sweep funds to address in the wallet
- Flee dangerous area
- Once safe, repeat above commands to recall the seed words to your wallet
- Sweep as necessary to another wallet with new device, multisig, backup etc.