HTTPS traffic is difficult to screen because it is encrypted using the SSL/TLS protocol, which secures the data in transit between the client and the server. This encryption ensures that any intercepted traffic cannot be easily read or tampered with by third parties. Screening or inspecting this encrypted traffic would require decrypting it, which poses significant challenges and potential security risks12.
Reference:
The concept of HTTPS and its implications on traffic screening are discussed in various cybersecurity resources, including Cisco's cybersecurity training materials3.
Cloudflare provides an explanation of HTTPS inspection and the challenges associated with it