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This subclause is the fourth group in the introduction, the one with no coupon strategy. Both parties do the work each time, which makes it simpler to operate and more sensitive to the cost of the arithmetic on a constrained device.

What it asks

Record the exchange and the device cost, and show that the verifier checks point membership and the response relation on every run. Test a point outside the subgroup and a replayed challenge, and record the measured device cost rather than an estimate.

What the revision does

The fourth edition will restate the exchange. No public copy of the new sequence exists yet. The 2009 wording is therefore superseded at publication.

Who it binds

The implementer and the capacity owner for the device estate.

Evidence an auditor samples

• The exchange sequence and the device cost measurement (test report)
• The point validation and response checks, with code pointers (source repository)
• The negative tests and their outputs (test report)

The test you can run

Measure the exchange on the slowest supported device. If the measurement is an estimate, the capacity case is unproven.

Common failures

• The device cost is estimated from a desktop benchmark.
• Subgroup validation is skipped to save time on the constrained device.

How to close it

Measure on the device you support, not the one on your desk. The absence of a coupon is a design choice, and the cost that comes with it has to be evidenced rather than assumed. Start with the exchange sequence and the device cost measurement and let the row close when it exists with a date and a named holder.

Where it sits against the 2009 edition

The 2009 edition carries 9.3, and the fourth edition replaces it. The public record does not give the new wording, so this page records the obligation that stands today and the question the revision has to answer.

For the file, this row closes when the exchange sequence and the device cost measurement exists with a date, a named holder and a pointer, and when the test above has been run and recorded. The implementer and the capacity owner for the device estate. owns that answer for 9.3.