ICP custody with seed phrase and air-gapped machine

Getting your hardware and software ready

What you will need:

1. air-gapped computer (not connected to the internet)
2. networked smartphone

You will need to install the following into your air-gapped computer:

1. `keysmith`

   - keysmith
   - You will use this generate important artifacts like `seed phrase` and `private key`s

1. `openSSSL`

   - [1](https://wiki.openssl.org/index.php/Binaries)
   - required by `quill`

1. `quill`

  - [2](https://github.com/dfinity/quill)
   - you will use this to craft messages like "create neuron" for the Internet Computer
   - You can install it by downloading the binary for your operating system or by cloning and compiling the code
   - note that once installed, the command to execute is `target/release/quill` 

1. `qrencode`

   - https://github.com/fukuchi/libqrencode) 
   - [3](https://github.com/fukuchi/libqrencode) 
   - Generates QR codes for bridging the air gap
   - Tip: if you have Homebrew, you can install via `brew install qrencode`

1. `jq`

   - [4](https://github.com/stedolan/jq) 
   - Required for creating multiple QR codes
   - Tip: if you have Homebrew, you can install via `brew install jq`

1. Copy and paste the following bash script into a file named `quill-qr.sh`:

Warning: Only tested on MacOSX and Linux.

```bash

1. !/usr/bin/env bash

URL=https://p5deo-6aaaa-aaaab-aaaxq-cai.raw.ic0.app IFS=$'\n' read -r -d -a messages < <( cat - | jq -M 'if . | type != "array" then [.] else . end' | jq -rcM .[] && printf '\0' )

for message in "${messages[@]}" do

   echo "$URL/?msg=$(echo "$message" | gzip -c | base64 | tr -d '\n' | sed -e 's/+/%2B/g' -e 's/\//%2F/g' -e 's/=/%3D/g')" | qrencode > qr.png
   open qr.png
   echo ENTER TO CONTINUE...
   read < /dev/tty
   clear

done ```

Because an air-gapped computer is not connected to the internet, it can be a bit awkward to install these. The most common way to do it is to download them to a networked computer and transfer the files to the air-gapped computer via CD or USB drive. Others install these on a networked computer *and then* air-gap it.