zkPhoto: Private Authentic Photo Sharing


This project demonstrates a small stepping stone toward #2 of Brian Gu’s Six ZK Moonshots. The idea is to have an on-chain data marketplace where users can trade private data, for example, “a high-res image that downsamples to a known low-res image”, using ZK.

Application Type


Proposal Overview

Within the scope of this proposal, the MVP is to implement a dApp that (0) use ZK to prove that the low-res image is downsized from an actual high-res image, (1) mint an NFT that contains the downsized image, as well as the hash of the original image, (2) implement an in-browser camera for authentic on-chain photo-taking, and more.

Use Cases

  1. NFT minting for everyone
    NFT has been seen as something exclusive to artists and their artworks. zkPhoto will allow everyone to mint an NFT directly from their phone using a camera.

  2. Private data marketplace
    One common criticism of NFT is that the original artwork is often publicly available for everyone to download. zkPhoto allows the proof of ownership of a high-resolution image while only keeping the low-resolution version on-chain.

Competitive Landscape

There is no similar product in the market as far as we know.

Proposal Ask

zkPhoto will become community-driven and self-funded by its own DAO and NFT sales. In order to get this up and running, we will be requesting the $15k/year stable basic income to take care of initial development, welfare, and operations costs.

This ask will be in line with the laid down milestones as detailed below

  1. launching a feature-complete product on our testnet
  2. forming a DAO with 5-out-of-9 multisig
  3. launching on mainnet with audit
  4. attracting 1k daily active users (with launch video, full PR promotion)
  5. attracting 10k daily active users (with a detailed roadmap, governance process)

Road Map

Objective Date Status
Testnet launch March 19th Done
Beta Testing and Fixes May 31st Pending
Smart Contract Audit June 30th Pending
Mainnet Launch August 31st Pending

External links

  1. zkPhoto Application on testnet
  2. circuits and contracts
  3. front end repo
  4. product page in Harmony’s notion

Demo video

Mainnet ETA

Mainnet launch will take place on August 31st, 2022.

We are actively looking for more members and active testers to join zkPhoto and its DAO.


this looks great, @socathie ! but may i recommend you push for an earlier mainnet launch, and also add forming a DAO in your timeline?

mainnet launch doesn’t have to mean final launch. it just means getting meaningful feedback earlier on.

“The first thing we always tell founders is to launch their product right away; for the simple reason that this is the only way to fully understand customers’ problems and whether the product meets their needs. Surprisingly, launching a mediocre product as soon as possible, and then talking to customers and iterating, is much better than waiting to build the “perfect” product. This is true as long as the product contains a “quantum of utility” for customers whose value overwhelms problems any warts might present.” ← a lot of good advice here too - YC’s Essential Startup Advice: Becoming a Founder, Early Stage, Talking to Users | Y Combinator

with that, i’d give a strong yes as a governor. very solid project here.


This is a great project, especially in the area of NFTs. Looking forward to the launch.

It’s a yes from me as a governor of zkDAO :+1:

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Amazing and unique idea.
Strong yes from me as governor of zkDAO.

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Great work Cathie. When launched on mainnet, this will be a game changer!
Big yes from me as a governor of zkDAO.

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Great idea!
Strong yes from me as governor of zkDAO

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Looking forward to the launch! Big yes from me as a governor of zkDAO.

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Looks dope! Yes from me.

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i see 6 positive votes from zkDAO governors here, which exceeded the 5 votes needed for funding. since the applicant has already reached milestone 1, we will start paying her DBI by the start of APR.

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Milestone 2

A DAO has been formed with a 5-out-of-9 multisig (address: 0xad5AF97a6Cff8899e94c35E865510Ed8c6487661) with the following mandates and founding governors:

zkPhoto DAO


  1. Advocate for further ZK applications in the NFT space and promote zkPhoto to reach a wider user base
  2. Build zkPhoto with more functionalities to achieve the ultimate goal of a private (image) data marketplace
  3. Catalyze innovation and development in ZK applications on blockchain by providing open-source tools and mentorship to similar projects

Founding Governors

Founder of zkPhoto, governor at zkDAO, and teaching staff at ZKU. Cathie is a public speaker and instructor on the topics of machine learning, blockchain, and web3 development in Hong Kong.

Digital artist and aspiring expressive arts therapist. Vivian contributes to the formation of the idea of zkPhoto. (Potential COI declaration: Cathie and Vivian are in a domestic relationship.)

Governor at zkDAO and course director of ZKU. Hakwan has over 14 years of experience in tertiary education. Besides working at Harmony as a core team member, he also directs the Laboratory for Consciousness at the RIKEN Institute (Center for Brain Science) near Tokyo.

Governor at zkDAO and teaching staff at ZKU. Semar also works at Webb-Protocol as a software engineer.

Governor at zkDAO and teaching staff at ZKU. Alex is a master’s degree student and TA at the Faculty of Technical Sciences in Novi Sad, Serbia.

Governor at zkDAO and teaching staff at ZKU. Tosin is a software engineer at a leading bank in Africa and contributing to the Harmony Blockchain in the areas of zero-knowledge proofs and privacy.

Teaching staff at ZKU. Elise is a software engineer at a fintech company based in Seattle, WA.

Former teaching staff at ZKU and a researcher studying the social and cognitive mechanics of science denialism. He is researching ways ZK can help Web3 promote healthy discourse and information ecosystems.

Student at ZKU and a seasoned scientific researcher. Seong started in cancer immunology, dabbled in computational neuroscience, and currently works on stroke outcome prediction.

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congrats. i think you have indeed reached milestone 2.

Congrats from me as well. Well deserved!

Congrats - I (as a zkDao governor) also confirm that milestone 2 had indeed been reached.

Congrats on successfully meeting the second milestone.

As a zkDAO governor, I confirm that milestone 2 has been reached.

5 zkDao governors confirmed that milestone 2 has been reached :slight_smile:

may i nominate this project for a Technical Innovation award. the reason is that the circuit involved here was custom built. if 4 or more other governors agree, then the requirements for achieving milestones 4 and 5 will be adjusted accordingly - Introducing Tehnical Innovation Grants

I support this nomination for a Technical Innovation award as a zkDao Governor!

I also support the nomination for a Technical Innovation award as a zkDAO Governor!

I support this nomination as a zkDAO governor