[_b8r0]

> So why does he need a VPN at the airport?

Because the airport made a shitty choice in designing it's wifi, and people who connect to such networks are making shitty choices.

HTTPS is nothing more than a content protocol wrapped in a transport encryption layer used for a subset of your overall traffic.

When you connect to an open wifi network your device is literally screaming 1s and 0s into the air like a maniac. A subset of these 1s and 0s are the things you're actively telling the computer to do. Most of this stuff is things like ARP, Name resolution services and other stuff that isn't encrypted for perfectly understandable reasons.

Instead, when connecting to an open airport wifi network, a personal decision is made that the connectivity is more important than encryption. Airport wifi connections could and should be encrypted with AP client isolation, but they aren't.

[m0dest]

How exactly is the airport supposed to offer a WiFi network that is encrypted and open without breaking usability and compatibility?

This hasn't been possible until WPA3, which has barely started rolling out.

[zamadatix]

OWE and an SAE PSK network with a well known PSK do not solve the trust issue of connecting to public Wi-Fi rather only the encryption issue.

Take the example that you are connecting to an SSID named "Airport_Guest_WiFi". In the case of OWE you simply connect and now everything between you and "Airport_Guest_WiFi" is encrypted. In the case of PSK with SAE you connect to "Airport_Guest_WiFi" and exchange information to generate secret keys only you two know. The problem in either scenario is you've just set up encryption not trust. How do you know the "Airport_Guest_WiFi" you connected to was the airports or the attackers?

WPA3 Enterprise solves this issue somewhat but is not realistic to deploy for temporary guest networks.

I argued ever since I heard OWE was going into draft it should have some optional mode for PKI validation. E.g. if you connect to the SSID "guestwifi.airport.com." and the airport signed the hello with the cert for that domain then the client could validate that against it's root stores and have the same level of identity trust it does when connecting to usersbank.com. Clients need not be forced to validate it but at least it gives a realistic option to connecting to such networks.

[CKN23-ARIN]

Many ways to do this.

Make the password widely-known. Announce it over the intercom. Post it on the walls.

Offer both encrypted and non-encrypted SSIDs. The non-encrypted SSID could even just be a captive portal with instructions to connect to the encrypted SSID.

If you're feeling wild, use WPA2 Enterprise, and accept any credentials.

[icebraining]

"WPA and WPA2 don't provide forward secrecy, meaning that once an adverse person discovers the pre-shared key, they can potentially decrypt all packets encrypted using that PSK transmitted in the future and even past, which could be passively and silently collected by the attacker. This also means an attacker can silently capture and decrypt others' packets if a WPA-protected access point is provided free of charge at a public place, because its password is usually shared to anyone in that place. In other words, WPA only protects from attackers who don't have access to the password."

https://en.wikipedia.org/wiki/Wi-Fi_Protected_Access#Lack_of...

[CKN23-ARIN]

Notably, this is only a problem for WPA2-PSK, not WPA2-Enterprise. But, fair enough -- this does render my first suggestion unsuitable.

[0xf00d]

Doesn't the widely-known password render the encryption useless to anyone that has captured the 4-way handshake at the beginning of your WIFI-session? With the PSK and your session keys an attacker can decrypt your traffic if I remember it correctly.

[0xf00d]

It is already possible using a combination of WPA Enterprise (802.1x) and RADIUS. The RADIUS server is configured to accept any username/password combination, effectively providing an open access point but isolating its users because the 802.1x scheme employs different key material for each user (not completely sure about that key material part but I think that's how it works).