Last Call Review of draft-ietf-lwig-minimal-esp-03
review-ietf-lwig-minimal-esp-03-secdir-lc-mandelberg-2021-04-01-00

I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the
IESG.  These comments were written primarily for the benefit of the
security area directors.  Document editors and WG chairs should treat
these comments just like any other last call comments.

The summary of the review is Ready with nits.

(Section 3, nit) In the paragraph that includes "However, nonrandom SPI 
and restricting their possible values MAY lead to privacy and security 
concerns" , it would be nice to add something like "(see below for more 
details)". When I first read that paragraph, I was about to comment that 
it's unclear what the privacy/security concerns are, but then it was 
explained a few paragraphs below.

(Section 4) Am I understanding correctly, that the last paragraph is 
giving the option of resetting the Sequence Number when rekeying? Does 
IPSec try to prevent eavesdroppers from determining when rekeying 
happens? (I really don't know that much about IPSec.) If it does, then 
resetting the SN could leak that information, if not then there's 
nothing to leak.