Update Serving encryption documentation to the newest developments

[ReToCode]

Proposed Changes

• Update Serving encryption documentation to the newest developments

/assign @dprotaso
/cc @nak3
/cc @skonto
/cc @KauzClay

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (7561386) 86.02% compared to head (6c424ed) 86.06%.
Report is 17 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #14631      +/-   ##
==========================================
+ Coverage   86.02%   86.06%   +0.04%     
==========================================
  Files         197      197              
  Lines       14929    14937       +8     
==========================================
+ Hits        12843    12856      +13     
+ Misses       1776     1772       -4     
+ Partials      310      309       -1     

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[ReToCode]

/retest

[skonto]

CN/SAN reference at the bottom should be removed or used to indicate the SAN name for an individual ksvc?
Just want to clarify that we are using SNI.

[skonto]

LGTM waiting for the others.

[ReToCode]

CN/SAN reference at the bottom should be removed or used to indicate the SAN name for an individual ksvc?
Just want to clarify that we are using SNI.

Done.

[dprotaso]

encryption-system-internal.drawio.svg

I think the 'use' arrows are inverted. Cause I don't think of a secret as using the activator - but the other way around.

[ReToCode]

I think the 'use' arrows are inverted. Cause I don't think of a secret as using the activator - but the other way around.

👍 Right, fixed it.

[dprotaso]

/lgtm
/approve

[knative-prow]

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