Based on my understanding of the TOR network, it currently cannot function without directory authorities. The directory authorities provide a signed list of all of the TOR network relays, and that includes the set of encryption certificates used for each relay and all of the configuration information about it.
The TOR clients come hard coded with a list of directory authorities. Without the ability to query the directory authorities they cannot find a usable TOR route. I don't know if there is some caching involved, but if not then this would effectively stop the network for anyone trying connect to TOR.
So why couldn't signed lists of relays just, say, float around on a DHT, with a cache-and-forward model like Freenet, but where newer documents (provided they're signed with the same key) will overwrite older documents in the same cache slot?
Actually, to put it another way, Freenet is itself the optimal bootstrapping mechanism for Tor. Maybe the two projects should merge, such that Tor would effectively be an optimization over the specific case of two peers generating and searching for one-another's signed Freenet documents (this effectively being an IP tunnel already).
It's already done that way. Tor relays cache signed consensus documents from the directory authorities. It doesn't change the fact that you need some trusted computers, somewhere, that give you an accurate view of the network.
I mean we have the "technology" to do distributed trusted computation (without trusted hardware). It would just be extremely difficult to bring it into the TOR project without rewriting large parts of it.
Storing and transmitting the consensus is not the issue. The issue is that you need to decide what relays get into the consensus. You also can't choose a system where different clients get different relay directories, or people will be able to profile clients by which relay directories they're using.
The TOR clients come hard coded with a list of directory authorities. Without the ability to query the directory authorities they cannot find a usable TOR route. I don't know if there is some caching involved, but if not then this would effectively stop the network for anyone trying connect to TOR.