To authenticate public publishers on Mainnet, you indeed need to run your own publisher or use one of the client SDKs. On Mainnet, there are no public publishers without authentication because they consume both SUI and WAL. Setting up your own publisher involves creating internal sub-wallets, using a Sui wallet to perform on-chain actions.

Yes, you would need to either run your own publisher or utilize a client SDK to manage the authentication process. This setup is necessary to control operations and costs associated with using SUI and WAL. For further details and understanding, you might also consider watching relevant resources like this YouTube video or referring to the Walrus documentation and setup guides.