COTI V2 Confidentiality Preserving L2 | SDKs and Examples

All repositories specified below contain smart contracts that implement confidentiality features using the COTI V2 protocol. The contracts provide examples for various use cases, such as Non-Fungible Tokens (NFTs), ERC20 tokens, Auction, and Identity management.

These contracts demonstrate how to leverage the confidentiality features of the COTI V2 protocol to enhance privacy and security in decentralized applications. The contracts are of Solidity and can be compiled and deployed using popular development tools like Hardhat and Foundry (Work in progress).

Important Links:

Docs | Devnet Explorer | Discord | Faucet

Interact with the contract using any of the following:

1. Python SDK | Python SDK Examples
2. Typescript SDK | Typescript SDK Examples
3. Hardhat Dev Environment

The following contracts are available in each of the packages:

Contract		python sdk	hardhat sdk	typescript sdk	Contract Description
AccountOnboard	deployment	✅ *	✅	❌	Onboard a EOA account - During onboard network creates AES unique for that EOA which is used for decrypting values sent back from the network
AccountOnboard	execution	✅	✅	✅	"
ERC20Example	deployment	✅	✅	❌	Confidential ERC20 - deploy and transfer encrypted amount of funds
ERC20Example	execution	✅	✅	✅	"
NFTExample	deployment	❌	✅	❌	Confidential NFT example - saving encrypted data
NFTExample	execution	❌	✅	❌	"
ConfidentialAuction	deployment	❌	✅	❌	Confidential auction - encrypted bid amount
ConfidentialAuction	execution	❌	✅	❌	"
ConfidentialIdentityRegistry	deployment	❌	✅	❌	Confidential Identity Registry - Encrypted identity data
ConfidentialIdentityRegistry	execution	❌	✅	❌	"
DataOnChain	deployment	✅	❌	❌	Basic encryption and decryption - Good place to start explorining network capabilties
DataOnChain	execution	✅	❌	✅	"
Precompile	deployment	✅	✅	❌	Thorough examples of the precompile functionality
Precompile	execution	✅	✅	❌	"

(*) no deployment needed (system contract)

Note

Due to the nature of ongoing development, future version might break existing functionality

Faucet

🤖 To request devnet/testnet funds use our faucet

Hardhat (confidential-contracts)

Note

Please refer to the latest tags to find the most stable version to use.

The confidentiality-contracts project is composed of three main components:

1. Reference libraries (located in contracts/lib): containts the MpcCore and MpcInterface libraries referenced by all other SDKs. These libraries contain instructions for methods which the gcEVM handles as bytecode. For a full description of the libraries visit the libraries readme.

2. gcEVM Precompiles (located in contracts/examples/precompiles): These are a set of examples that make use of the reference libraries mentioned above. For a full description of these precompiles visit the precompiles readme.

3. Example contracts (located in contracts/examples): the examples folder contain Solidity contracts that perform various use cases, such as Non-Fungible Tokens (NFTs), ERC20 tokens, Auction, and Identity management. It contains smart contracts that implement confidentiality features using the COTI V2 protocol.

The following example contracts are available for Hardhat Runtime Environment for deployment and execution:

Contract	Contract Description
AccountOnboard	Onboard a EOA account - During onboard network creates AES unique for that EOA which is used for decrypting values sent back from the network
ERC20Example	Confidential ERC20 - deploy and transfer encrypted amount of funds
NFTExample	Confidential NFT example - saving encrypted data
ConfidentialAuction	Confidential auction - encrypted bid amount
ConfidentialIdentityRegistry	Confidential Identity Registry - Encrypted identity data
Precompile	Thorough examples of the precompile functionality

Usage

ERC20Example

The following process will help you run the ERC20Example.sol example from the COTI confidentiality-contracts project. The contract defines a custom ERC20 token called ERC20Example that extends the functionality of the ConfidentialERC20 token. Additionally it will:

• Create a EOA (Externally Owned Account)
• Validate minimum balance

The contract is compiled and deployed with Hardhat using the confidential-erc20.test.ts test suite contained in the test-hardhat directory of the project.

Note

Ensure your environment meets all the pre-requisites. Visit the pre-requisites section of the readme.

1. Clone the confidentiality-contracts repo

   git clone https://github.com/coti-io/confidentiality-contracts.git

2. Change directory to the newly create one

   cd confidentiality-contracts

3. Install dependencies

   yarn

4. Build and compile contracts

   yarn build

5. Run the test-erc20 test suite

   yarn test-erc20

   Running this test will automatically create an account and a key/value pair with name: SIGNING_KEYS (visible in the .env file). The script will output something like this:

   yarn run v1.22.22
   
     Confidential ERC20
       1) "before all" hook in "Confidential ERC20"
   
     0 passing (39ms)
     1 failing
   
     1) Confidential ERC20
          "before all" hook in "Confidential ERC20":
        Error: Created new random account 0x17EDB982c3569D29EbaF407F72aDD05722d5f179.
        Please use faucet to fund it.

   
   It is normal to receive the exception Error: Created new random account [...] Please use faucet to fund it. on the first run. This will be resolved once the account is funded.

6. Head to the faucet at https://faucet.coti.io to get devnet funds.
   Send the following message to the BOT using your newly created account, visible in the last part of the response.
   
   devnet <account address>
   
   The bot will reply with the message:
   
   <username> faucet transferred 10 COTIv2 (devnet)
   

7. Run the test-erc20 test suite once more.

   yarn test-erc20

   
   The script output will look like this:

   Confidential ERC20
   ************* Onboarding user  0x17EDB982c3569D29EbaF407F72aDD05722d5f179  *************
   ************* Onboarding user  0xe1E7315F6970F353661fc84FFd9238133cED3677  *************
   ************* Onboarded! created user key and saved into .env file *************
   ************* Onboarded! created user key and saved into .env file *************
       Deployment
         ✔ Deployed address should not be undefined
         ✔ Owner initial balance (123ms)
         ✔ Function 'name' should be correct (130ms)
         ✔ Function 'symbol' should be correct (123ms)
         ✔ Function 'decimals' should be correct (119ms)
         ✔ Function 'totalSupply' should be correct (117ms)
       Transfer 5
         ✔ Transfer - clear (9469ms)
         ✔ Transfer - Confidential (5260ms)
         ✔ TransferFrom - clear without giving allowance should fail (9905ms)
         ✔ TransferFrom - clear (9770ms)
         ✔ TransferFrom - Confidential (10265ms)
         ✔ Approve/Allowance - Confidential (10255ms)
   
     12 passing (1m)
   
   ✨  Done in 69.69s.

Running the test suite does the following:

• Deploys the ERC20Example contract: Sets up the token with specific details (name, symbol, initial supply).
• Tests the deployment: Verifies the contract address, initial balance, and token details (name, symbol, decimals, total supply).
• Tests transfers: Both clear and confidential transfers, including transferFrom functionality with and without prior allowance.
• Tests approvals and allowances: Ensures that the contract correctly handles approvals and allowances, both clear and confidential.

8. You may also run specific tests

   yarn test-nft
   

   or

   yarn test-erc20
   

   or

   yarn test-auction
   

   or

   yarn test-identity
   

   or

   yarn test-precompiles
   

Add contracts to your Hardhat project

yarn add git@github.com:coti-io/confidentiality-contracts.git

This command installs the confidentiality contracts from the specified Git repository using the Yarn package manager for Hardhat projects. After installation, you can import and use the contracts in your Solidity code.

To report issues, please create a github issue