async function init() {

    const operations = crypto.subtle

    const KEY_LEN = 256

    const ENCRYPTION_ALGO = "AES-GCM"
    const ENCRYPTION_USAGES = ["encrypt", "decrypt"]
    const ENCRYPTION_PARAMS = { name: ENCRYPTION_ALGO, length: KEY_LEN }

    const WRAPPING_ALGO = "AES-KW"
    const WRAPPING_USAGES = ["wrapKey", "unwrapKey"]

    const DERIVATION_ALGO = "ECDH"

    const { publicKey, privateKey } = await operations.generateKey(
        {
            name: DERIVATION_ALGO,
            namedCurve: "P-384",
        },
        false,
        ["derivekey"]
    )

    const encryptionKey = await operations.deriveKey(
        {
            name: DERIVATION_ALGO,
            public: publicKey,
        },
        privateKey,
        ENCRYPTION_PARAMS,
        false,
        ["encrypt"]
    )

    const decryptionKey = await operations.deriveKey(
        { name: DERIVATION_ALGO, public: publicKey },
        privateKey,
        ENCRYPTION_PARAMS,
        false,
        ['decrypt']
    )

    return { encryptionKey, decryptionKey }

}


function stringToArrayBuffer(str) {
    var buf = new ArrayBuffer(str.length);
    var bufView = new Uint8Array(buf);
    for (var i = 0, strLen = str.length; i < strLen; i++) {
        bufView[i] = str.charCodeAt(i);
    }
    return buf;
}


function arrayBufferToString(str) {
    var byteArray = new Uint8Array(str);
    var byteString = '';
    for (var i = 0; i < byteArray.byteLength; i++) {
        byteString += String.fromCodePoint(byteArray[i]);
    }
    return byteString;
}


async function aEncryptWithKey(key, data) {
    // Encrypt data with key. Return a Promise
    return new Promise((resolve) => {
        window.crypto.subtle.encrypt(
            {
                name: "AES-GCM",
                iv: stringToArrayBuffer(key.uuid),
            },
            key.key,
            stringToArrayBuffer(data)
        ).then(text => {

            resolve(btoa(arrayBufferToString(text)));

        });
    });
}

function encryptWithKey(key, data) {
    // Encrypt data with key. Return a Promise
    return new Promise((resolve) => {
        window.crypto.subtle.encrypt(
            {
                name: "AES-GCM",
                iv: stringToArrayBuffer(key.uuid),
            },
            key.key,
            stringToArrayBuffer(data)
        ).then(text => {

            resolve(btoa(arrayBufferToString(text)));

        });
    });
}


function decryptWithKey(key, data) {
    // Decrypt data with key. Return a Promise
    return new Promise((resolve) => {
        window.crypto.subtle.decrypt(
            {
                name: "AES-GCM",
                iv: stringToArrayBuffer(key.uuid),
            },
            key.key,
            stringToArrayBuffer(atob(data))
        ).then(text => {

            resolve(arrayBufferToString(text));

        });
    })
}