If a search query on your data would contain all the components of the original hash, i don't have to walk backwards and break the hash. i just have to hash my query terms in the same way.
Also I suggested you store the daily hash forever. But even if you really erase it every day, as you say, If you or an attacker makes the same request every day at a predetermined time, when you/they get your logs, you/they can use that predictable request to get the daily secret too.
I consider the information to be stored in plain text, and that you would have to have requested permission just the same. You pretty much have an identifiable user (via IP/UA/access time) stored in your logs.
Anonymization is removal of information, not encoding it in a convoluted hash.
Also I suggested you store the daily hash forever. But even if you really erase it every day, as you say, If you or an attacker makes the same request every day at a predetermined time, when you/they get your logs, you/they can use that predictable request to get the daily secret too.
I consider the information to be stored in plain text, and that you would have to have requested permission just the same. You pretty much have an identifiable user (via IP/UA/access time) stored in your logs.
Anonymization is removal of information, not encoding it in a convoluted hash.