Can someone help me how to use events/logs for proof of publication? The way I understand it, I send a transaction with the metadata I want "proof of publication" for, to a contract. The contract does not update its state (ie. The metadata is not stored in its storage). But does there need to be anything in the contract to generate the log? Or is it easier to just aggregate all the transactions sent to that address and extract the metadata using the list of transactions?
I'm looking for the cheapest way (in gas) to log small bits of information and have it associated with a specific address/contract. Any help and suggestions are appreciated!