Cake Technologies Zcash Mobile Wallet Design & Development

Applicant Background

Cake Technologies, LLC is the company behind Cake Wallet, a noncustodial, open-source wallet for Bitcoin, Litecoin, and Monero. Cake Wallet has close to 200,000 users and has been around since January 2018. Cake Wallet is available on iOS and Android.

With this grant, Cake Technologies would like to build a Zcash wallet that:

  1. Is compatible with NU5 and Halo Arc
  2. Heavily prioritizes using shielded addresses and fully shielded transactions
  3. Uses a simple interface similar to the existing Cake Wallet UI
  4. Is available for both iOS and android

Motivation and Overview

Cake Wallet is one of the most used privacy-conscious mobile wallets. Cake Wallet is completely open source.

We believe that a dedicated Zcash wallet will allow Zcash to take advantage of Cake's development efforts, integrations, and user base. As Cake expands its integrations, users of this Zcash wallet can benefit these features for minimal cost and effort from the Zcash community.

Technical approach

The Cake development team will start with the existing UI design of Cake Wallet and incorporate core Zcash features into the same design. From there, the Cake team will polish the application with highly-requested features and test the application for reliability.

Core wallet features / functionality

  • Send ZEC to shielded addresses
  • Send ZEC to transparent addresses (with significant warning)
  • Receive ZEC to shielded addresses
  • Backup wallet with mnemonic seed
  • Send transactions with an optional included encrypted memo
  • Ability to generate and save new z-addresses under the same seed

Exchange options

Cake already supports instant exchanges between cryptocurrencies (including ZEC) using ChangeNOW. This integration auto-populates a user's desired address to facilitate trades. Cake will work with ChangeNOW to support fully shielded transactions, but this is out of scope of this proposal.

Cake is undertaking work to integrate with Thorchain, a decentralized exchange that allows users to swap assets through semi-trusted, distributed nodes.

Cake Technologies has worked with several states to build a dedicated Cake Exchange. Initially, this will allow users to buy ZEC with credit/debit cards in these select states. We hope to expand Cake Exchange to include user sales of ZEC and to include more states. Users will be able to have Zcash delivered directly in their shielded addresses.

Easily pay human-friendly addresses

Cake supports looking up human-readable addresses using the OpenAlias, Unstoppable Domains, and Yats. This allows users to save time by typing in human-friendly items such as donate@z.cash, z.cash, or even emojis. The wallet will then look up to see if there are ZEC addresses associated with those items and return the full address.

This is a natural fit for Zcash, since z-addresses can be reused without worry of transactions being identified/linked.

What are the milestones?

Though this project, Cake Technologies will take the feature-rich base of Cake Wallet and adapt them to work for Zcash.

Milestone 1: Expand developer team, wallet proof of concept Milestone 2: Deliver reliable ZEC wallet with core send/receive/backup functionality Milestone 3: Polishing bells and whistles on ZEC integration (Cake Exchange, Thorchain, other miscellaneous)

How will the work we fund support the Zcash mission - i.e. to bring financial privacy to everyone in the world?

Cake Technologies has been bringing privacy to ordinary people since January 2018. We want to build a feature-rich, simple-to-use Zcash mobile wallet for both major mobile platforms to allow for the Zcash community to continue to grow. The application will be open source, and it will integrate with other projects that the Zcash community is interested in, including Thorchain (which has a pending ZOMG proposal already). These integrations will push Zcash users to get far more involved in the Zcash ecosystem besides just being a HODLer.

Deliverables:

  • Make the wallet available on App Store, Play Store, and direct APK download with regular updates.
  • All code & designs will be open-sourced with MIT license on GitHub.
  • Updates following every milestone on the Zcash Forums.

Execution Risks and Downsides

There are risks that the Zcash blockchain upgrade schedule is delayed or changed for any reason. Regarding Thorchain integration, Cake can only add ZEC once the existing Thorchain proposal is complete.

Budget and justification

This 6 month budget funds 4 full time developers and several part time contributors

  • $200,000: 5 full time developers
  • $50,000: 2 part time support staff

Campaign

Started
7 days ago
Funding
$250,000 
Funded through  Zomg logo
1
Wallet proof of concept
2
Wallet with core send/receive/backup
3
Wallet integrations

Wallet proof of concept

Reward: $62,500
Hire additional developers and have a Zcash wallet proof of concept with core sending/receiving functionality for iOS and Android.

Payment Request

The team may request a payout for this milestone at any time.