Do a normal product with a time-based license key.
Results are read-only without a valid key. Don't encrypt the data as it will irritate all your users. People will want to review results during the event, if only to verify that it was correct. Or contest results a few days later. In races, people are sometimes disqualified even months later - I don't know about weightlifting.
On the other hand, new input/modifications require a valid key.
Keys are renewed either automatically (with an online license check / renewing payment) or through an online purchase which returns a license key to input.
You can have a start/end date to the license to bracket the event, with a few days/weeks on either side for flexibility.
Note: I've never done anything like this; these are proposal only.
Results are read-only without a valid key. Don't encrypt the data as it will irritate all your users. People will want to review results during the event, if only to verify that it was correct. Or contest results a few days later. In races, people are sometimes disqualified even months later - I don't know about weightlifting.
On the other hand, new input/modifications require a valid key.
Keys are renewed either automatically (with an online license check / renewing payment) or through an online purchase which returns a license key to input.
You can have a start/end date to the license to bracket the event, with a few days/weeks on either side for flexibility.
Note: I've never done anything like this; these are proposal only.