SSL ensures that the data transmitted between the server and the browser is encrypted - make sure to set it up by checking the box located in the
Settings > Domain/email section of the Bubble Editor.
Having robust privacy rules is essential in making sure that your server doesn't set data to a browser that the user is not supposed to see. See link below for more information about setting those up.
We also have a video walkthrough for Bubble Privacy Rules.
In Bubble, you can create a popup that blocks the user from visually seeing or interacting with the page. However, these popups can be closed relatively easily using Developer Tools in the browser.
To put this in specific "Bubble-ese": you shouldn't rely on a popup with the setting
This popup can't be closed by pressing Esc to lock users out of pages.
If your application needs to store very sensitive data, like Social Security numbers, credit card numbers, etc. in encrypted format. Better yet, find another company (like Stripe or Paypal) that can handle these very risky transactions, and integrate them into your app through Bubble plugins or using the API Connector.
Bubble does encrypt all data at rest, which makes data storage and data usage more safe if you have authentication and privacy rules properly set up. But if you've accidentally made your privacy rules more loose than they should be, someone may get a hold of your data. We would recommend encrypting the values that go into those sensitive fields yourself and then decrypting them before they're used.
Define a password policy functionality found in
Settings > General section of the Bubble editor to set the minimum length, capital letter requirements, etc.
If you need to make an API call that uses a secret key or a token, make sure that it's not populated on any page but is instead in one of these 2 places:
In the API connector, marked as "Private"
In an API workflow
This will ensure that the user's browser never sees the API key/token.
If you're interested in learning more about how Bubble secures data in general, and some other security recommendations, you can read these security guidelines from early 2019 posted in the Bubble Forum by Josh (Bubble CTO and co-founder).
To test whether privacy rules are set up correctly, it can be helpful to use a web browser's developer tools to examine what data is available to the user. Here's a page that shows how to do that with Chrome.