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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. So the annex keeps its base text and gains this material, which a copy of the base annex will not have.
- 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. Put the design note, separating requirement from claimed feature in the register first, then work down the evidence list until every line has a date.
- Where it sits against the base standard
- The annex exists in the base standard and the amendment extends it. A copy of the base annex is not the current annex, so the citation must name the amendment as well as the edition.