const encrypt = (text, key) => {
    return Array
        .from(text)
        .reduce((acc, char) => acc.concat(char.charCodeAt().toString(2)), [])
        .map(bin => '0'.repeat(8 - bin.length) + bin )
        .map(binary => binary ^ key)
        .join(' ')
};

const decrypt = (binary, key) => {
    return binary
        .split(' ')
        .map(bin => parseInt((bin ^ key),2))
        .map(bin => String.fromCharCode(bin))
        .join('')
};

const secret = 'akunamatata';
const binary = encrypt('hello', secret);
decrypt(binary, secret);