[ippm] Alissa Cooper's No Objection on draft-ietf-ippm-6man-pdm-option-09: (with COMMENT)

[Alissa Cooper <[e-mail]>]

Alissa Cooper has entered the following ballot position for
draft-ietf-ippm-6man-pdm-option-09: No Objection

When responding, please keep the subject line intact and reply to all
email addresses included in the To and CC lines. (Feel free to cut this
introductory paragraph, however.)


Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
for more information about IESG DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-ippm-6man-pdm-option/



----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

The analysis in Sec 4.2 seems to be missing some considerations. In cases
where the packet payload is encrypted and the attacker does not have
access to the keys, the attacker does not in fact have access to the
entire packet, in which case PDM provides more information than a packet
without PDM. Also in those cases, it seems like including PDM information
would generally make a packet stream more susceptible to traffic analysis
insofar as the timing and sequence information may provide additional
indicators about the type of application in use, not just the speed of
the end host.