Clause 7.2: Skinny encryption

What the clause requires

What the public text does not state

• The body of clause 7.2
• The Skinny round function and its constants

What it means for you

This is the forward direction for the Skinny family and the clause an implementer reads alongside the version table. The public text gives the title and the page, and nothing else. The record does not describe the round function, the S-box, the rotation table or the number of rounds, because none of that is in the sample.

The absence is worth stating plainly because the internet is full of descriptions of Skinny from the research literature, and a page written from those would look authoritative and be uncheckable against the standard. The record s rule is that a page either cites the public text or says the text is not in the public preview. This page takes the second route.

What a buyer can still do is ask the right question. A conformance claim for Skinny encryption should come with a known-answer test from Annex A, a version and a round count. Those three items are enough to start a review even before the purchased text is on the desk, and they are the items the record asks for.

Evidence to keep

What an auditor or a customer is likely to ask for

Artefact	Owner	Why it matters
Known-answer test for the forward direction and the version in use	Engineering	The annex is the check the standard supplies.
Round count and configuration per version	Engineering	A version name without a round count is incomplete.
Purchase record for the base standard, so clause 7.2 can be read	Standards owner	The clause cannot be reviewed against a text nobody holds.

How to verify it

Ask for the test vector and the round count. If the team can produce neither, the claim rests on a library name.

Dates

The kit plan for clause 7.2 sets the evidence review at 17 June 2027, 90 days before the estimated publication date of 15 September 2027.

Cross references

• 7 Skinny
• 7.1 Skinny versions
• 7.3 Skinny decryption
• A.3 Skinny-64/192 example
• A.4 Skinny-128/256 example
• A.5 Skinny-128/384 example

Where this comes from