I’m doing DPI on my own network and I can still view TLS certificate fingerprints and some metadata that provides a good educated guess as to what a traffic flow contains. It certainly better that it’s encrypted, but there is a little information that leaks in metadata. I think that’s what was meant.
I think it might be confusion between inspecting plaintext metadata like SNI vs actually inspecting encrypted contents (e.g. HTTPS content, headers, etc.).
How is DPI a problem if it’s encrypted? That would only work if the attacker had installed their CA cert on your client machine, right?
I’m doing DPI on my own network and I can still view TLS certificate fingerprints and some metadata that provides a good educated guess as to what a traffic flow contains. It certainly better that it’s encrypted, but there is a little information that leaks in metadata. I think that’s what was meant.
I think it might be confusion between inspecting plaintext metadata like SNI vs actually inspecting encrypted contents (e.g. HTTPS content, headers, etc.).
Yeah, deep packet inspection really doesn’t work without breaking https security via man in the middling everything.