I am studying the same topic and I have found the following:
1) Key ID is the last 8 or 16 characters of fingerprint according to what version of Key ID you use - short or long. You can check it experimentally by creating gpg.conf in your ~/.gnupg directory with string:
Type the command "gpg --list-key --with-...
This RSqueezA sounds okay to provide QR Codes and read from them to a key file.
But: In my company non-technical people get a long (about 32 random characters) key phrase printed as-is. And then the paper will be stored in a (fire-proof) safe.
Reading and typing all the characters is good and fast enough for them.
For all the other people without a safe I ...
You cannot do it offline.
This kind of problem is solved on blockchain solution by using consensus (on permissionless blockchains) or a centralized database (on permissioned ones). Otherwise, I could receive 5 FakeCoins from someone, and give them to 10 people, multiplying the coins. By using a consensus algorithm, this multiplication is not possible: the ...