What method can Palo Alto firewalls employ to classify encrypted web traffic?

To classify encrypted web traffic, Palo Alto firewalls utilize SSL Decryption. This method allows the firewall to intercept and decrypt secure traffic (HTTPS), enabling it to inspect the contents for potential threats or policy violations. By decrypting the data, the firewall can apply its security policies, identify applications, and block or allow traffic based on its content, which is crucial for maintaining security in environments where encrypted traffic is prevalent.

SSL Decryption is particularly effective because a significant portion of today's web traffic is encrypted. This capability not only enhances visibility into encrypted traffic but also aids in ensuring compliance with security protocols. The firewall can then re-encrypt the data after inspection, maintaining the confidentiality of the information in transit.

Other methods like IP Filtering, Packet Inspection, and Content Tunneling do not directly engage with the decryption of SSL/TLS traffic. IP Filtering focuses on source and destination IP addresses, while Packet Inspection involves analyzing packet headers and payloads that are already visible. Content Tunneling typically refers to encapsulating data within another protocol, which does not apply to the classification of encrypted web traffic in the same context as SSL Decryption.