Storing a salt with 24h expiry would be the same thing as the solution in the article. It would be better from a privacy perspective because the IP would then not be transmitted in a reversible way.
If I hadn't asked for permission to send hash(ip + date) then I'd sure not ask permission if I instead stored a random salt for each new 24h and sent the hash(ip + todays_salt).
This is effectively a cookie and it's not strictly necessary if it's stats only. So I think on the server side I'd just invent some reason why it's necessary for the product itself too, and make the telemetry just an added bonus.
If I hadn't asked for permission to send hash(ip + date) then I'd sure not ask permission if I instead stored a random salt for each new 24h and sent the hash(ip + todays_salt).
This is effectively a cookie and it's not strictly necessary if it's stats only. So I think on the server side I'd just invent some reason why it's necessary for the product itself too, and make the telemetry just an added bonus.