I keep hearing on VPN ads that you have to use a VPN to not have your login information stolen. So far I have been using Cloudflare WARP to be safe enough. However, if I am using an HTTPS website, do I really need a VPN or WARP? Will an attacker on the same network as me be able to access passwords transmitted over HTTPS?
Non-Internet analogy:
You communicate via snail mail with someone. Both ends know the address of each other. So does the postal service delivering your mail. Everyone opening your letter can read (and with some work even manipulate) the content. That’s HTTP.
Now you do the same, but write in code. Now the addresses are still known to every involved party but the content is secured from being read and thus from being manipulated, too. That’s HTTPS.
And now you pay someone to pick up your mail, send it from their own address and also get the answers there that are then delivered back to you. The content is exactly as secure as before. But now you also hide your address from the postal service (that information has the guy you pay extra now though…) and from the one you are communicating with. That’s a VPN.
So using a VPN doesn’t actually make your communication more secure. It just hides who you are communicating with from your ISP (or the public network you are using). Question here is: do you have reasons to not trust someone with that information and do you trust a VPN provider more for some reason? And it hides your address from the guy you are communicating with (that’s the actual benefit of a VPN for some, as this can circumvent network blocks or geo-blocking).
Long story short: Do you want to hide who you are communicating with from the network you are using to access the internet? Then get a VPN. The actual data you send (and receive) is sufficiently secured by HTTPS already.
You know that VPN traffic is encrypted, right?
But encrypting already encrypted HTTPS data is largely irrelevant (for that simplified analogy) unless you don’t trust the encryption in the first place. So the relevant part is hiding the HTTPS headers (your addresses from above) from your the network providing your connection (and the receiving end) by encrypting them.
Unless of course you want to point out that a VPN also encrypts HTTP… which most people have probably not used for years, in fact depending on browser HTTP will get refused by default nowadays.