this is what I would like to achieve, I looked for a plugin but found nothing really good for me.

I am creating a site for my wedding day and I want to share it with my guests.

My idea is to give each guest a unique QR-code that they can scan and they find themselves logged with their names in the site, so I’m able to customize the pages accordingly to their name (something such as "hello Roger, welcome") and to handle the roles to show the correct invitation to everybody (lunch guests, pool-party guests etc). In this way I will be able to create each account prior to the event, assigning the correct type to each user.

The thing is, I want the user to scan-and-log, to keep my invitation letter design cool (without adding ugly name and password data) and to avoid people to mess around trying to log in.

How can I achieve this?

The alternative, that I would like to avoid, is to have a unique QR-code that bring the user to the login page and pre-fill at least the username field. Then under the QR-code I will print the password to use, or I will use a standard password for everybody.

I don’t care about security, users will not be able to do anything than reading the pages, so I don’t care if somebody else could sniff credential or similar.