BITE-solidity

A Solidity Library for building smart contracts that leverage BITE 2 on SKALE.

Introduction

Solidity library for building smart contracts that leverage SKALE's BITE 2 blockchain capabilities. It exposes wrappers around the BITE-specific precompiled contracts for threshold encryption (TE), ECIES encryption, and conditional transaction (CTX) submission, plus the callback interface that contracts must implement.

Installation

Use as a package dependency

Add to your own Hardhat or Foundry project:

yarn add @skalenetwork/bite-solidity
# or
npm install @skalenetwork/bite-solidity

Usage

For detailed usage, integration patterns, and end-to-end examples, see examples/README.md. The examples are organized as a Yarn workspaces monorepo — each example is a thin workspace member that reuses shared Hardhat config, TypeScript config, and script utilities from the workspace root.

Disclaimer: Code under examples/ is not production-ready and is provided for educational and demonstration purposes only.

Important: If your contract interacts with BITE precompiles, compile with EVM version istanbul for now.

Legacy Solidity support

If your project targets an older Solidity compiler, import the matching legacy file instead of BITE.sol:

File	Minimum Solidity version
BITE.sol	>=0.8.27
LegacyBITE.sol	>=0.8.5
VeryLegacyBITE.sol	>=0.8.4
VeryVeryLegacyBITE.sol	>=0.8.0
VeryVeryVeryLegacyBITE.sol	>=0.6.0
VeryVeryVeryVeryLegacyBITE.sol	>=0.5.0 <0.6.0

For Solidity <0.6.0, also use LegacyTypes.sol (which wraps PublicKey inside a Types library) and LegacyIBiteSupplicant.sol instead of their modern counterparts.

Additionally, for a larger real-world example, see the SKALE confidential-token repository and how it leverages bite-solidity.

Example

// SPDX-License-Identifier: AGPL-3.0-only

pragma solidity ^0.8.26;

import { Address } from "@openzeppelin/contracts/utils/Address.sol";
import { BITE } from "@skalenetwork/bite-solidity/BITE.sol";
import { IBiteSupplicant } from "@skalenetwork/bite-solidity/interfaces/IBiteSupplicant.sol";

contract Example is IBiteSupplicant {
    using Address for address payable;

    bytes public decryptedMessage;
    bytes public encryptedMessage;
    address public ctxSender;

    error AccessViolation();

    // Input encrypted off-chain using @skalenetwork/bite-ts library, or use `encryptedMessage`
    function decrypt(bytes calldata cipher) external payable {
        bytes[] memory encryptedArgs = new bytes[](1);
        encryptedArgs[0] = cipher;

        bytes[] memory plaintextArgs = new bytes[](0);

        ctxSender = BITE.submitCTX(
            BITE.SUBMIT_CTX_ADDRESS,
            msg.value / tx.gasprice,
            encryptedArgs,
            plaintextArgs
        );

        payable(ctxSender).sendValue(msg.value);
    }

    function encrypt(bytes memory message) external {
        encryptedMessage = BITE.encryptTE(
            BITE.ENCRYPT_TE_ADDRESS,
            message
        );
    }

    // onDecrypt will usually include sensitive operations
    // It is important to always cross-check the sender is correct
    function onDecrypt(
        bytes[] calldata decryptedArgs,
        bytes[] calldata /* plaintextArgs */
    ) external override {
        require(msg.sender == ctxSender, AccessViolation());
        ctxSender = address(0);

        decryptedMessage = decryptedArgs[0];
    }
}

Other References & Useful Links

• SKALE Network Documentation
• BITE V2 Protocol Documentation

License

AGPL-3.0-only

This project is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

See LICENSE for full terms.