Zcash Weekly Developers Update 3-11-17

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By Paige Peterson

The beginning of the week saw the timely release of 1.0.7. There was a minor issue in how we executed the release process this time around which resulted in a 1.0.7-1 version that was put out later in the week. If you haven’t yet upgraded from 1.0.6, we highly recommend doing that now. If you’re on 1.0.7, upgrading to 1.0.7-1 is not urgent but we suggest doing so anyway!

We’re making good progress on Payment disclosure and hope to include an experimental version available in the 1.0.8 release. This version will include a privacy leak that will take some more time to address and therefore we recommend those who want to experiment with this feature be clear about the lesser-privacy aspects. A blog post outlining the initial version of Payment disclosure will be released in time for it’s availability.

We’re also making headway on Payment off-loading and hope to have an experimental version ready for 1.0.8 as well. We discussed whether the initial version of this feature should start its experimental phase as a stand-alone server-side application, built separately and configured to connect to a zcashd client.

XCAT research and proof-of-concept writing is continuing as well with a draft ZIP in the works. We most likely won’t see any XCAT experimental integration into 1.0.8 but we’re making progress on the necessary HTLC improvements to Zcash and Bitcoin. We have a soon-to-be-released blog post which will have more information on theses necessary improvements to allow for cross-chain trading.

We released the crypto upgrade overview for the future Sapling series of releases in a blog post. This change will make shielded payments more efficient and less memory intensive while improving the security of the cryptography used in generating zero-knowledge proofs.

We’re continuing to work on our privacy and security guidelines for users. There’s a lot of concepts to cover here with various different types of risk models to consider but we hope to have a concise version of these guidelines (internally dubbed a “crash course”) out early next week with a more detailed document published soon after. As part of researching these privacy considerations (particularly in the network analysis side of things), we will be looking for feedback when a few Zcash team members head to the semi-annual Tor meeting in a couple weeks. We are very appreciative of their invite to us to join their meeting and look forward to any mutual support our teams (and networks) can give to one another!
General user documentation is also going through a make-over with continued work on united zcash-cli documentation and transferring non-developer documentation from the Github wiki to the website.

Relatedly, we had a topical meeting this week on the RPC design in which we reviewed our legacy decisions forking from bitcoin and brainstormed about how to best execute any future RPC interface depreciation. We also decided that we would update payments from transparent address which have change to go back to original address rather than creating a new address as standard with bitcoin. This will make transparent address use more explicitly transparent. The new address for each change output standardized in bitcoin is a weak attempt at user privacy, one we do not feel comfortable supporting anymore in Zcash.

And finally, some research was started on multi-sig support in shielded addresses and our ongoing protocol security research continued. Expect part 2 of our zk-SNARK explainer blogs sometime next week!