Home / The record / Asymmetric encryption systems

This family builds authentication on an asymmetric encryption system rather than on a bare one way function. It is the only family in the part with a mutual exchange, so it is the one to read when both parties have to be assured of each other rather than one of the other.

What it asks

Record whether each deployment is unilateral or mutual, and show that the mutual exchange really gives both parties assurance rather than running two unilateral exchanges back to back. Keep the encryption system parameters with the mechanism record, because the two are chosen together.

What the revision does

The fourth edition keeps the family and will restate it. The revised text is not public. The 2009 wording is therefore superseded at publication.

Who it binds

The architect who chose the mechanism and the operator of the mutual service.

Evidence an auditor samples

• The deployment record, naming unilateral or mutual (architecture)
• The exchange diagram with both assurance points marked (design note)
• The encryption system parameters and their review (cryptography standard)

The test you can run

In a mutual deployment, ask what the first party knows at the end that it did not know at the start. If the answer is nothing, the exchange is not mutual.

Common failures

• Two unilateral exchanges are presented as mutual authentication.
• The encryption system is chosen by the vendor and never recorded.

How to close it

Draw the assurance, not the messages. A mutual exchange is defined by what each party knows at the end, and a diagram with two arrows can hide the absence of it. Put the deployment record, naming unilateral or mutual in the register first, then work down the evidence list until every line has a date.

Where it sits against the 2009 edition

The clause exists today as Clause 8 in the 2009 edition. The fourth edition replaces it, and the public record stops before the new wording, so the obligation below is the one in force.

For the file, this row closes when the deployment record, naming unilateral or mutual exists with a date, a named holder and a pointer, and when the test above has been run and recorded. The architect who chose the mechanism and the operator of the mutual service. owns that answer for Clause 8.