Zero Network

See the Grants Program Process on how to submit a proposal.

• Team Name: Zero Network
• Payment Address: 0x9061b0787D28d0fDaD845d670F7505EAE5F3B01B (DAI)
• Level: 2
• Status: Terminated

Project Overview 📄

We would like to implement a parachain which specializes in privacy.

This parachain supports confidential transfers and privacy preserving smart contracts on the mainchain based on the plonk. To support privacy, the traditional blockchains need to implement L2 solutions, complex contract logic or depend on centralized security assumption. The L2 technologies often sacrifice the usability, the complex contract logic cost too much gas and development workload, and the centralized security assumption force us to believe someone you have never met before. As the solution for these problems, we are going to implement parachain supporting privacy on mainchain and depending on only cryptographic hardness assumption. The documentation is here.

Overview

Through this grant, we would like to implement confidential transaction functionalities for both transfers and smart contract executions. There are two types of privacy confidential and anonymous. In this scope, we support the confidential transactions which hide the input and output. The anonymous hides the users related to the transaction. The anonymous is going to be supported in the future. We provide the confidential transactions for both transfer and contract execution.

Project Details

This parachain privacy preserving protocol relys on the cryptographic hardness assumptions. There are some components consisting this system and We divide the components as following.

• primitive: Basic cryptography libraries necessary for the network.

• functionality: Confidential transactions pallets to realize the privacy.

• module: Developer tools to develop the confidential smart contracts and output the constraints metadata.

• client: Wallet libraries to transfer and execute the confidential smart contracts.

We describe the detail as following.

Primitive

The primitive provides crypto libraries necessary for functionality as pallet.

1. Lifted-ElGamal encryption pallet
2. zk-SNARKs plonk pallet which supports the plookup and aggregation proof on top of ZK-Garage/plonk
3. Encrypted balance pallet

Functionality

The functionality provides the confidential transfers and confidential smart contracts functions as pallet.

1. Confidential Transfer pallet
2. Condidential Smart Contract pallet

Module

The module provides the developer with tools and necessary libraries managing privacy application.

1. Encrypted ink!
2. Contract constraint builder
3. Proof generation library
4. Confidential smart contract IDE

Client

The client provides the transactor client libraries for users.

1. Key generation wallet
2. Decrypt and encrypt transaction and balance
3. Create zero knowledge proof of plonk
4. Confidential transfers
5. Confidential smart contracts executor

Use Case

We explain the use case we assume.

Ecosystem Fit

This is the world's first account based and plonk built-in parachain which supports confidential transactions for both transfers and contract executions only depending on the cryptographic hardness assumptions. We can contribute to Polkadot network mainly in three ways.

• 1. High performance and Polkadot friendly cryptography primitive

Our team has been working on zk-SNARKs probjects for long time so we are sure that we can contribute to implement cryptography pallets confidential smart contracts, homomorphic encryption and so on which require a high degree of skill and these will be used for many developers. Most parts of them are composed by cutting edge technologies for example plonk which supports plookup and proof aggregation, and encryption library which supports somewhat homomorphic encryption so we can catch up them. Especially, we have been working on prover time optimization using speed up algorithm, assembly and parallelize, and also exprienced implementing plonk as pallet so we can design the fastest encryption primitive which is Polkadot friendly no_std and parity SCALE Codec compatible.

• 2. Privacy preserving XCMP

We are planning to connect this blockchain to Polkadot as parachain after redesign and optimization. We will be able to use these blockchain functionalities in the entire network. It means that all parachain in Polkadot network can use privacy preserving transactions. We think that this is huge benefit for Polkadot network users because they can easily use the confidential transactions whatever parachain they use.

• 3. Research and development

We would like to improve privacy and scaling using cryptographic scheme. We are going to do experiment about rollup transactions and block compression for storage scaling, Fully Homomorphic Encryption and MPC for privacy. Especially the Fully Homomorphic Encryption will be the next hot topic we are going to focus on.

Similar Project

There are some similar projects. We compare their features.

Comparison

The most valuable point is that we implement zero knowledge friendly blockchain. The main problem of confidential smart contract projects is the gas limit problem. The additive homomorphic encryption and zk-SNARKs are using heavy arithmetic workload and these processes often exceed the gas limit so it's important to design the blockchain as zero knowledge friendly structure. To make it practical, we think that the Substrate is suitable for three reasons. The account base blockchain, customizable Wasm and zero knowledge scheme.

The prover side, the more simple structure we generate the zero knowledge proof, the more efficiency we get. The account base blockchain using the key value mapping so it's more efficient than UTXO. We can save the prover time with account based structure.

The verifier side, we need to optimize the virtual machine performing the zero knowledge function to define case specific bytecode. We can customize the bytecode and get benefit from efficiency of Wasm VM.

Considering both sides, the zero knowledge scheme is related deeply to calculation workload and the zk-SNARKs is the most efficient one but has a setup scheme. Previously, the zk-SNARKs setup parameters depended on circuit so we needed to setup parameters when we deployed some new contracts. It's hard to ensure that there are enough parties for each deploy contracts so almost contract base confidential smart contract project uses the bulletproof. However, we use the plonk which can generate the parameters without depending on circuit so once we setup the parameters, we can reuse that parameters for every transaction with getting profit of zk-SNARKs efficiency.

Team 👥

Team members

• Ash Whitehat
• Kirill Karbushev

Contact

• Contact Name: Invers Inc
• Contact Email: info@invers.tech
• Website: Invers

Legal Structure

• Registered Address: 2F・3F Emblem Nishiarai, 3-33-6 Umejima, Adachi City, Tokyo-to 121-0816, Japan
• Registered Legal Entity: Invers Inc.

Team's experience

Our company is working on the blockchain scaling and information hiding technologies. We already delivered several grants with Astar Network.

• zk-rollups
• zk-plonk

Team Code Repos

• Zero Network
• Ash Whitehat
• Kirill Karbushev

Team LinkedIn Profiles

We are not on LinkedIn.

Development Status 📖

The information about this project and what we did are following.

• The documentations about this project is here.
• The plonk pallet implementation.
• The documentation describing the details.

Development Roadmap 🔩

Through this grant, we are going to develop the blockchain which supports confidential transactions for both transfers and smart contract executions.

Overview

• Total Estimated Duration: 6.5 months
• Full-Time Equivalent (FTE): 2 FTE
• Total Costs: 45,000 DAI

Milestone 1 | Confidential Transfers

• Estimated duration: 2 month
• FTE: 2
• Costs: 10,000 DAI

In Milestone 1, we are going to implement confidential transfer pallet on top of balance pallet. With this pallet, the user can transfer the asset with hiding input and output with Lifted-ElGamal encryption.

Number	Deliverable	Specification
0a.	License	Apache 2.0 / GPLv3 / MIT / Unlicense
0b.	Documentation	We will provide both inline documentation of the code and a basic tutorial that explains how users send the confidential transfers.
0c.	Testing Guide	Core functions will be fully covered by unit tests to ensure functionality and robustness. In the guide, we will describe how to run these tests.
0d.	Docker	We will provide Dockerfiles that can be used to test all the functionality delivered with this milestone.
0e.	Article	We will publish an article/tutorial/workshop that explains
1.	Lifted-ElGamal pallet	We are going to implement Lifted-ElGamal pallet which allows our calculation to remain encrypted. The Lifted-ElGamal allows us multiple addition and one time multiplication for encrypted number.
2.	encrypted-balance pallet	We are going to implement encrypted-balance pallet which allows us to store the balance encrypted by Lifted-ElGamal encryption. The encrypted-balance allows us to hide whole network user's balance.
3.	plonk pallet	We are going to implement plonk pallet which allows us to use plonk on Substrate. In confidential smart contracts execution, the plonk need to support lookup and aggregation proof.
4.	confidential-transfer pallet	We are going to implement confidential-transfer pallet which allows us to send transactions without revealing any information of it.

Milestone 2 | Confidential Smart Contract Executions

• Estimated Duration: 3 month
• FTE: 2
• Costs: 25,000 DAI

In Milestone 2, we are going to implement confidential smart contract execution pallet on top of contracts pallet and ink!.

Number	Deliverable	Specification
0a.	License	Apache 2.0 / GPLv3 / MIT / Unlicense
0b.	Documentation	We will provide both inline documentation of the code and a basic tutorial that explains how users send the confidential smart contracts.
0c.	Testing Guide	Core functions will be fully covered by unit tests to ensure functionality and robustness. In the guide, we will describe how to run these tests.
0d.	Docker	We will provide Dockerfiles that can be used to test all the functionality delivered with this milestone.
0e.	Article	We will publish an article/tutorial/workshop that explains
1.	zk-contracts pallet	We are going to implement zk-contracts pallet which allows us to execute deployed contract WASM binary on top of contracts pallet.
2.	zk ink! eDSL	We are going to implement confidential smart contract eDSL on top of ink! which allows developer to develop the confidential smart contract.
3.	zk ink! compiler	We are going to implement zk ink! compiler on top of cargo-contract which allows developer to compile and deploy the confidential smart contract.
4.	zk ink! metadata	We are going to implement zk ink! metadata on top of ink_metadata which generate the contract constraint statement for zk contract used when the user create the proof.
5.	zk-contracts pallet	We are going to implement zk-contracts on top of contract pallet which allows runtime to execute deployed contracts.
6.	zk-contracts-rpc pallet	We are going to implement zk-contracts-rpc pallet on top of pallet-contracts-rpc pallet which allows the blockchain to have interface interacting with deployed contracts.

Milestone 3 | Confidential Transaction Wallet

• Estimated Duration: 1.5 month
• FTE: 2
• Costs: 10,000 DAI

In Milestone 3, we are going to implement wallet which provides the user to interact with blockchain, send transactions and manage the secret on locally.

Number	Deliverable	Specification
0a.	License	Apache 2.0 / GPLv3 / MIT / Unlicense
0b.	Documentation	We will provide both inline documentation of the code and a basic tutorial that explains how users participate network and send transaction.
0c.	Testing Guide	Core functions will be fully covered by unit tests to ensure functionality and robustness. In the guide, we will describe how to run these tests.
0d.	Docker	We will provide Dockerfiles that can be used to test all the functionality delivered with this milestone.
0e.	Article	We will publish an article/tutorial/workshop that explains
1.	Key generation	We are going to implement key generation libraries which allow user to generate key with random and store the secret on locally.
2.	ElGamal crypto utils	We are going to implement ElGamal encryption libaries which allow user to decrypt and encrypt transaction and balance.
3.	plonk proof generation	We are going to implement plonk proof generation which allows user to create proof for circuit constraint.
4.	Confidential transfer	We are going to implement confidential transfer libraries.
5.	Confidential smart contract execution	We are going to implement executing smart contract libraries.

Timeline

Milestone	Deliverable	Estimated Duration (month)	Deadline
1	Confidential Transfers	2	2023 1/7
2	Confidential Smart Contract Executions	3	2023 4/7
3	Confidential Smart Contract Executions	1.5	2023 5/26

Future Plans

• Rollup transactions
• Compress block with zero knowledge proof
• High performance and Polkadot friendly plonk library
• Anonymous transactions
• Wasm optimization

Additional Information ➕

• How did you hear about the Grants Program?
  • Announcement by another team
• Work you have already done.
  • plonk pallet
• Wheter there are any other teams who have already contributed (financially) to the project.
  • No.
• Previous grants you may have applied for.
  • zk-rollup
  • zk-plonk