Merge pull request #21 from ASCS-eV/feat/verifiable-and-privacy-preserving-delegated-onchain-execution

Feature: verifiable and privacy preserving delegated onchain digital asset publication

Author: sid030sid

packages/trust-anchor-did-ethr/.gitignore

@@ -61,4 +61,8 @@ build/
 
 # --- Testing ---
 reports/
-.nyc_output/
+.nyc_output/
+
+# Ignore files generated by circom-ecdsa fork in order to comply with gpl-3 license
+contracts/verifiers/*
+circom-zkp-generator/*

packages/trust-anchor-did-ethr/README.md

@@ -15,6 +15,29 @@
 4. only all trust anchor admins together can call the changeOwner function of their companys' did:ethr identifier (stage of feature: Implemented, Tested, Reviewed)
 5. one trust anchor admin uses the deployed DIDMultisigController contract of its trust anchor to add a static pointer to a smart contract that enables company admins to change the CID of BFC of company's CRSet by calling the setAttribute function on the "service" section of the company's did:ethr identifier (stage of feature: Implemented, Tested, Reviewed)
 
+## Desired feature for private digital asset publication
+This feature of the DIDMultisigController smart contract enables a company admin to show a Zero-Knowledge Proof that authorizes the DIDMultisigController to act as a relayer and digital asset publisher without revealing the identity of the authorizing company admin.
+
+### Set up and testing private digital asset publication
+To unlock the feature for private digital asset publication, the Zero-Knowledge Proof generator must be added to this ``trust-anchor-did-ethr`` package, which can be done following the steps described in the ``README`` of the [ASCS circom-ecdsa fork](https://github.com/ASCS-eV/circom-ecdsa?tab=readme-ov-file#private-secure-on-chain-group-signature-verification-with-variable-group-size). After adding the Zero-Knowledge Proof generator to the folder `./circom-zkp-generator`, the feature for private digital asset publicaiton can be tested by running `npx hardhat test ./test/DIDMultisigController.privatePublish.test.ts` in the terminal while in the folder `./packages/trust-anchor-did-ethr`.
+
+### Workflow of private digital asset publication
+1. **Preparation**: The Trust Anchor admin uses the [ASCS circom-ecdsa fork](https://github.com/ASCS-eV/circom-ecdsa) to create ZKP-verifier smart contracts (see `./contracts/verifiers`) and ZKP generator (see `./circom-zkp-generator`) specific to different group sizes. To create both, follow the [instructions from above](#set-up-and-testing-private-digital-asset-publication).
+2. **Registration**: The Trust Anchor deploys these verifier smart contracts and stores their addresses in the `verifiers` mapping within the `DIDMultisigController`.
+3. **Generation**: Company admins (or a DApp) generate a ZKP off-chain using the ASCS toolset (see `./circom-zkp-generator`).
+4. **Publication**: Admins call `privatelyPublishMarketplaceData` to publish digital data assets to the ASCS marketplace (simulated via `DigitalAssetMarketplaceStub`).
+
+**Note:** see test script `./test/DIDMultisigController.privatePublish.test.ts` to understand the code behind the workflow steps of *registration*, *generation*, and *publication*.
+
+### Improvements for future
+The goal is to make verifier registration obsolete by making membership proofs independent of group size, as discussed in the [ASCS circom-ecdsa fork](https://github.com/ASCS-eV/circom-ecdsa) under "Membership Proof Is O(m)". 
+
+Alternatively, a **Fixed-Size Padding** model could be used:
+* **Simpler contract architecture**: Only one verifier contract (e.g., fixed at 100 slots) is maintained.
+* **Easier extensibility**: Smaller groups are padded with null-address placeholders.
+* **Reduced complexity**: Client-side logic remains consistent across all group sizes.
+* **Lower overhead**: Fewer artifacts (WASM, zkey) need to be managed.
+
 ## Desired security features for production
 ### ... for identity of trust anchor
 1. trust anchor admins cannot administer company DID of other trust anchor
@@ -24,45 +47,10 @@
 1. company admins cannot administer DID of trust anchor or other company
 2. ...
 
-## Usage of Hardhat
-
-### Running Tests
-
-To run all the tests in the project, execute the following command:
-
-```shell
-npx hardhat test
-```
-
-You can also selectively run the Solidity or `node:test` tests:
-
-```shell
-npx hardhat test solidity
-npx hardhat test nodejs
-```
-
-### Make a deployment to Sepolia
-
-This project includes an example Ignition module to deploy the contract. You can deploy this module to a locally simulated chain or to Sepolia.
-
-To run the deployment to a local chain:
-
-```shell
-npx hardhat ignition deploy ignition/modules/Counter.ts
-```
-
-To run the deployment to Sepolia, you need an account with funds to send the transaction. The provided Hardhat configuration includes a Configuration Variable called `SEPOLIA_PRIVATE_KEY`, which you can use to set the private key of the account you want to use.
-
-You can set the `SEPOLIA_PRIVATE_KEY` variable using the `hardhat-keystore` plugin or by setting it as an environment variable.
-
-To set the `SEPOLIA_PRIVATE_KEY` config variable using `hardhat-keystore`:
-
-```shell
-npx hardhat keystore set SEPOLIA_PRIVATE_KEY
-```
+## Acknowledgements
+We extend our gratitude to **0xParc** for their pioneering work on [circom-ecdsa](https://github.com/0xPARC/circom-ecdsa). Their implementation served as the foundational building block for the ZKP-based private digital asset publication system featured in this repository.
 
-After setting the variable, you can run the deployment with the Sepolia network:
+To meet the specific requirements of the `trust-anchor-did-ethr` software system, we have adapted 0xParc's original code within our own [fork of circom-ecdsa](https://github.com/ASCS-eV/circom-ecdsa). This fork is instrumental in our workflow, specifically for:
 
-```shell
-npx hardhat ignition deploy --network sepolia ignition/modules/Counter.ts
-```
+* **Verifier Smart Contracts**: Generating the ZK-SNARK verification logic located in `./contracts/verifiers`.
+* **ZKP Artifacts**: Producing the circuit compilation and proving keys found within the `./circom-zkp-generator` directory.