On 09 Jun 2020, alterego said the following...

I met a couple of people in a downtown coffee shop & we all showed
each other our drivers licenses (this was before smartphones, so
there was no risk of them taking a picture of the ID), we had a
coffee and a few hours later I got an email saying they had signed
my key, and I signed theirs.

You probably don't even need to exchange IDs to "prove" who you are to each other. What would the paper IDs really prove anyway? Documents can be faked.

Instead, when you are all meeting in person, just announce that you (person A) just sent an encrypted message to person B with the string "321" or something. When person B receives that and verifies a few seconds later then you have confirmation that you just "identified" the sender.

Btw.. did anyone wonder about the asymetrical pattern that was used on the parachute for the recent Mars landing?

"Clark, a crossword hobbyist, came up with the idea two years ago. Engineers wanted an unusual pattern in the nylon fabric to know how the parachute was oriented during descent. Turning it into a secret message was �super fun,� he said Tuesday."
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