# Annex H Claimed features, and what a claim is worth

Annex H lists the claimed features of the mechanisms so that a reader can choose one, and the amendment updates it for EdDSA. The features include compact signatures, the option of batch verification and resistance to a weak randomizer and to key substitution. They are claims in an informative annex, not requirements on an implementation.

## What it asks

Where a design note relies on a claimed feature, state that it is claimed in an informative annex and give the test that shows the property in your implementation. Do not present a claimed feature as a requirement, and do not assume batch verification exists because the annex lists it.

## What the amendment does

Updates Annex H.

## Who it binds

The author of the design note and the reviewer who approves the claim.

## Evidence an auditor samples

- The design note, separating requirement from claimed feature (architecture)
- The test that demonstrates any claimed property relied on (test suite)
- The review note that records the distinction (review log)

## The test you can run

Pick a claimed feature the design relies on. If there is no test that shows it, the claim is being treated as a guarantee.

## Common failures

- Batch verification is assumed to be available because the annex names it.
- A claimed resistance is repeated in a customer document as a certification.

## How to close it

Informative annexes are where marketing language enters a compliance file. Keep requirement and claim in separate columns, and cite the annex as informative whenever a claim is repeated outside the engineering team.

## Source

ISO/IEC 14888-3:2018/FDAM 1:2026(en), draft, Annex H. Read on 21 October 2026. Our wording, not the instrument's.
https://www.iso.org/standard/89517.html

Not legal advice; does not certify.