Decrypting WiFi packets on a public hotspot [closed]
Solution 1:
Web-based login pages do not affect 802.11 in any way. It's just a website. Yes, it controls the router's firewall to let you through, but it cannot enable encryption at 802.11 level.
If it's a fully open network, then there's no encryption at 802.11 level at all – you'll see plain TCP/IP. (But you probably won't see passwords, as any self-respecting site uses TLS (HTTPS). And TLS is not encrypted with your username nor password.)
If the network uses either WPA or WPA2 in WPA-Personal (WPA-PSK) mode, you can decrypt another client's 802.11 frames if you've captured its initial handshake with the wireless access point. (WPA3 will prevent this.)
If the network uses WPA-Enterprise (WPA-EAP) mode, you cannot generally decrypt anyone else's 802.11 traffic, as they have individual keys issued by the EAP server.