2
$\begingroup$

According to the Wikipedia page for NSA (emphasis mine):

However, NSA's Fortezza hardware-based encryption cards, created for the Clipper project, are still used within government, and NSA ultimately published the design of the SKIPJACK cipher (but not the key exchange protocol) used on the cards.

However, the NIST publication describing SKIPJACK also describes a Key Exchange Algorithm (KEA).

My question is simple: Is the Wikipedia page wrong, or is it talking about something else?

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ FWIW, the Wikipedia page no longer includes that remark. It was apparently added in this edit back in 2007, and removed in this recent edit, which also added a citation to the NIST publication you link to. $\endgroup$
    – Ilmari Karonen
    Jul 25, 2013 at 22:21

1 Answer 1

Reset to default
2
$\begingroup$

Wikipedia is wrong in this case - just like the NIST publication describing SKIPJACK already implies by being titled "SKIPJACK and KEA Algorithm Specifications". In fact, on page 17 of that paper, you will find infos about KEA exchange for Email and on page 12, there's a summary of a full KEA exchange between devices A and B…

A summary of a full KEA exchange between devices A and B (page 12)

A summary of a full KEA exchange between devices A and B

A summary of an Email KEA exchange between devices A and B (page 17)

A summary of an Email KEA exchange between devices A and B

On a side-note: If you check the Wikipedia entry, it shows that Wikipedia entry has been edited meanwhile, just like @ilmari-karonen already mentioned in a comment.

Improve this answer
$\endgroup$
2
  • 1
    $\begingroup$ So this is more or less two Diffie-Hellman key exchanges (both half-ephemeral for the full KEA, one half-ephemeral and one static for the email variant) in parallel, with an application of a "strange hash" (build from Skipjack encryption) on the result. $\endgroup$
    – Paŭlo Ebermann
    Jul 31, 2013 at 19:00
  • $\begingroup$ @PaŭloEbermann Correct. The Clipper Chip itself used the Skipjack encryption algorithm for transmission of information, and the Diffie-Hellman key exchange algorithm for distribution of the cryptographic session keys between peers. $\endgroup$
    – e-sushi
    Jul 31, 2013 at 20:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.