hah – impeccable timing as it almost feels like a planted question given we’ve been seeking a review of our whitepaper. Luckily, @bgits, you’ve been around these forums for a while, so definitely not a planted question! 
This is an approach Constitution DAO could have taken using Obscuro:
Create a contract that holds the funds on Obscuro, inflows/outflows, and the total balance would be known to nobody, all hidden away in encrypted rollups on Ethereum and inside secure TEEs.
Users would commit funds into the contract using encrypted transactions, indistinguishable from other transactions happening on the network.
The contract would have a function; let’s call it “doYouBid()”; which the auction house (or the party executing the auction) would need to be explicitly authorised at the outset to call using their key only in a predefined interval.
During the auction, the auctioneer would call this function at every step, passing in the next bid amount, e.g. doYouBid(13,000,000), doYouBid(14,000,000), etc. The function would only ever respond yes to the limit of its available funds (or some preconfigured limit that is also hidden).
After the auction, the auction house can claim the funds from the contract.
The other bidders cannot know the maximum amount locked in the DAO and thus have no advantage.