SPV and Z transactions


I’ve been this morning watching a live video with Linda about Zcash and tried to ask her one question at the end of the live stream but the chat feature from Youtube was really problematic!

The question is, to Linda or any other person:
Since in the video you spoke about ZCash reaching everybody, what’s the plan for ZCash to reach billions of people offering cheap transactions and simple to use wallets?

During the video Linda spoke about the light wallets and I wonder if there is any technique to implement SPV wallets for Z transactions without wiving away your privacy, that is, sending and receiving Z transactions without running a node.

As a user, no matter how geeky I am, I really don’t want to run a node. If ZCash can scale the way Bitcoin Cash will, leaving all the heavy load to the miners, it’ll be by far my favourite coin. SPV wallets is a must have if ZCash were to scale by increasing the block size as eventually running full nodes will require a relatively high effort (not that it’s easy now for an average person).

For any person interested, this two videos from the Bitcoin Unlimited developers are great:

@maesitos I did forward this thread to Linda, not sure why she hasn’t had time to respond.

As far as Z addresses and SPV wallets go, the most progress has been made by Guarda. You can find more info here:

I suggest reading all the way through this issue, lot’s of good stuff: Guarda Zcash light wallet · Issue #16 · ZcashFoundation/GrantProposals-2017Q4 · GitHub

In addition to that check out this thread which contains some links and discussions about z-addrs and SPV wallets (or lack thereof) Looking to make a Zcash wallet?

Some points after watching the vid:

1 - Where is ZCashD - no links to be found

2 - Is ZCash trying to be a charitable organization? I appreciate the mission of economic opportunity for all. However, altruism only goes so far.

3 - Because of point 2, what is being done by Zcash people to get “Suzie Soccer Mom” to use it to buy shoes, Starbucks or a new SUV? To me it does not sound like much.

4 - Because of 2 and 3, what is being done to get sellers of shoes, coffee and SUV’s to conduct retail transactions with ZCash?

If the ZCash people are looking for this to grow organically, it will not happen. Zcash must be sold actively to consumers and merchants.

Thank you, Linda, for the video!

zcashd is a binary that is part of the Linux zcash package. You can install it as explained here Download Zcash | Zcash but you need to use Linux and the command line. Sending a Z transaction like that is actually not my cup of tee for daily transactions

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WinZec is a windows version which is also a full node for the desktop. It is made for windows (port) and easy to install. It includes a GUI interface so you don’t have to use command line.

Hello @maesitos, sorry for the delay in reply.

We’re currently working on Zcash SPV wallets in a limited capacity–that is, we’ve hired contractors to provide Zcash SPV support for OpenBaazar, the decentralized marketplace. Currently, you need to be running a full node to use Zcash on OpenBaazar, which I agree is not very convenient.

Like @Shawn mentioned, Guarda has conditionally committed to working on SPV Zcash integration. They are happy to do so once overwinter and sapling make it feasible for mobile wallets to run the computations required for shielded addresses and if they receive continued funding for their work (I’m not in charge of this, but I had a good experience working with them and personally don’t see why they wouldn’t receive funding from Zcash foundation).

Currently, the only way to use shielded addresses is to use the Zcashd client (only for linux) or to use WinZec (there are some issues with that, from what I’ve heard, but I haven’t had a chance to use it). We’re focusing on getting Overwinter (Overwinter - Zcash) done and then Sapling done before we focus on making SPV wallets, since it is a pre-requisite for making SPV wallets that work on mobile and desktop clients.

One of our teams is also working to make zcashd build on multiple OSes, but I’m not sure how that work is going since I’m not on that team.


1: Oops, I didn’t link it in the description. It was my first video, so I forgot.

2: Zcash Company is a for-profit company that maintains the protocol and consensus rules for the time being. Zcash foundation (https://z.cash.foundation/) is a non-profit that aims to grow the Zcash community and specifically fight for people who need financial support the most.

3: It is frustrating to not see any good Zcash wallets out there, and we think that this is why people aren’t using it more. But there are other things we need to work on to make sure we have good wallets in the future. We’re working on making network upgrades safe (Overwinter upgrade; Overwinter - Zcash), and allow shielded transaction to be supported on mobile devices/ without running a full node (Sapling upgrade). We regularly evaluate and reach out to wallets that support Zcash and report bugs for wallets like Jaxx and Exodus (they have taken our feedback and fixed those). We’re also specifying what an ideal Zcash wallet should look like, although we have no commitments to build out own wallet yet.

4: We’re in communications with point of sales system vendors, and have gotten some (like Pundix; [ANN] Pundi X POS to support Zcash | by Pundi X (writers) | Pundi X | Medium) to support Zcash. Pundix specifically needs more time to roll out their product and is not on the market yet. But we’re strategically talking to people who would make vendor adoption easier.

Thanks for the concerns!

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Then is it possible to have SPV wallets for shielded transactions?

Thank you.