CiviCRM Community Forums (archive)

Hi,

Our goal is to add a qrcode on the badge.
Both for the organisers (being able to check who attended the second day by scanning them at the door) and for the participants to echange "business bards".

It seems that trying to cram a VCARD on the qrcode won't work, so I think about putting a URL, hosted on our server that serves the vcard.

http://example.org/qrc/{$contact.id}?{$contact.checksum}

Likely I'm going to encode the contact id in base 62, so that's more compact using as well a-z A-Z instead of only the 0-9.

The url can't be limited in the time, so I can't use the generateChecksum (that, and I'd want to be fast fetching the list of participants when I generate the badges, I'd rather be close to the db).

I don't want to put the hash directly, so thought about using as the "checksum"  the MD5 of the hash (so can't reverse to the hash).

Do you see a flow (privacy or security)? suggestion to make it better?

One flow I see is that if you merge the contact, you loose the vcard (not a big deal IMO) and that you can guess the size of the db by the contact id (and/or if the vard is from an "old record").

X+

Probably not a bid deal to base 62 indeed.

It seems that there is already an infinite lifespan (inf).

This being said, the size seems to matter (the qr code isn't read properly if too dense), but the normal checksum is only adding a few extra chars.

X+