Founder of Bitsquare here...
We have already added Zcash to our supported coins. So would be great to see some ZCashers there!
Bitsquare is a desktop application available for all majore OS using a custom P2P network (similar to Bitcoins P2P network) over Tor (hidden services). But no Tor setup required, it is integratd in Bitsquare. Bitsquare protects your privacy and you don't need to register. It is open source (AGPL) and not run by a company or VC funded but a community project.
Bitsquare never holds users funds. The funds are either in the users control or in a Multisig (the Bitcoin side).
The exchange process is similar like at LocalBitcoins but fully decentralized.
Bitsquare handles the transfer of the altcoin out of system, that makes it a no-brainer for us to add a new coin.
The security of the exchange is based on the same mechanisms which are used for Fiat exchanges.
2of3 Multisig, security deposit and an arbitration system. Please read the white paper for more info.
If anyone wants to trade Zcash on Bitsquare he simply adds an account for Zcash which requires only the Zcash address and then creates an offer or takes an existing offer for buying or selling ZEC against BTC. The transfer of ZEC is done by the BTC buyer from his external ZEC wallet to the BTC sellers ZEC address.
Hope to see you on our network!