"no side channels" subsection issues

[pes10k]

This issue is being filed as part of the requested PING review and was broken off from this previous issue

One sub-section is called "no side channels." I found this text confusing since, i. the text in the section seems mostly unrelated to side channels, and ii. "no side channels" is a goal, not a design feature (at least w/o some form of formal modeling thats not present in this spec, and not common in specs).

[anssiko]

@pes10k thanks again. This section was inherited from the earlier version of the API and benefits from a refresh.

I recommend this section to be split into a description of the generic side-channel attack in this context (if deemed relevant for the revised API) and its mitigation, both parts rewritten.

The generic for this split discussed in #204.

[anssiko]

This was fixed by #216

The confusing "no side channels" section was removed as part of the Security and privacy considerations reorganization.