lit.js

const ethers = require('ethers');
const LitSDK = require('lit-js-sdk/build/index.node.js');

const lit = new LitSDK.LitNodeClient();
await lit.connect();

const chain = 'mumbai';

const saveAuthSig = {
    sig: "0x<signature1>",
    derivedVia: "web3.eth.personal.sign",
    signedMessage:
        "Sign-in Message",
    address: "0x<address1>",
};

const accessControlConditions = [
    {
        contractAddress: '',
        standardContractType: '',
        chain,
        method: '',
        parameters: [
            ':userAddress'
        ],
        returnValueTest: {
            comparator: '=',
            value: '0x<address1>'
        }
    },
    {"operator": "or"},
    {
        contractAddress: '',
        standardContractType: '',
        chain,
        method: '',
        parameters: [
            ':userAddress'
        ],
        returnValueTest: {
            comparator: '=',
            value: '0x<address2>'
        }
    },
];


const { encryptedString, symmetricKey } = await LitSDK.encryptString("this is a secret message");

const encryptedSymmetricKey = await lit.saveEncryptionKey({
    accessControlConditions,
    symmetricKey,
    authSig: saveAuthSig,
    chain,
});

const saveEncryptedString = ethers.utils.hexlify(new Uint8Array(await encryptedString.arrayBuffer()));
const saveEncryptedSymmetricKey = ethers.utils.hexlify(encryptedSymmetricKey);


console.log(`encryptedString: ${saveEncryptedString}`);
console.log(`encryptedSymmetricKey: ${saveEncryptedSymmetricKey}`);


console.log(`DECRYPTING...`);

const restoreAuthSigProvider = {
    sig: "0x<signature2>",
    derivedVia: "web3.eth.personal.sign",
    signedMessage:
        "Sign-in Message",
    address: "0x<address2>",
};

const decryptSymmetricKey = await lit.getEncryptionKey({
    accessControlConditions,
    toDecrypt: saveEncryptedSymmetricKey.substr(2), // strip leading '0x'
    chain,
    authSig: restoreAuthSigProvider,
});


const decryptedString = await LitSDK.decryptString(
    new Blob([ethers.utils.arrayify(saveEncryptedString).buffer]),
    decryptSymmetricKey);

console.log(`Decrypt result: ${decryptedString}`);