If you want to have a hidden reserve, then is this method the best in imo:
Publish a sha256 hash of the hidden reserve (+ salt) in the beginning of auction.
At the end of the auction then do you reveal your hidden reserve (+salt) and everybody can see
that it matches the hash published in the beginning.
It's a good idea, but the hash can be decrypted at the beginning of the auction, so the reserve price is no longer secret.