Subject: [ietf-tls] Re: MISTY1 and CAMELLIA Ciphersuites

From: "Hidenori Ohta" <[email-masked]>
Date: Fri, 1 Dec 2000 18:05:11 +0900

> What is the general opinion about the proposed MISTY1 and CAMELLIA
> ciphersuites?

I'd like to explain about MISTY1.

1. Intellectual Property Right
There is the royalty-free license of MISTY1, but it does not fit with RFC2026.
Mitsubishi Electric Corporation decides that it should be modified.
The license, which follows RFC2026, that is to say non-encumbered, will be
appeared by the end of this year.

2. Cryptanalytic Consideration
MISTY1 is the first algorithm concering about both differential and linear
cryptanalysis.  It was designed on the basis of the theory of "provable
security".  It was also carefully designed to withstand various
cryptanalytic attacks that were known at the time of designing.  It was
published in 1996.  Since the publication of MISTY1, many research efforts
have been done for evaluating its security level; for example, higher order
differential cryptanalysis, slide attack, impossible differential cryptanalysis,
Luby-Rack off style evaluation, and so on.  However, no security flaws of
MISTY1 have been found.

MISTY1 is now widely used in many commercial and governmental
application.  Additionally, the 3rd generation partnership project
(3GPP) adopted a variant of MISTY1, which is called KASUMI, as a
mandatory algorithm in the confidentiality and integrity mechanisms of the
forthcoming W-CDMA systems.

Regards
--
Hidenori Ohta

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From: "Hidenori Ohta" <[email-masked]>
Date: Fri, 1 Dec 2000 18:04:12 +0900

Hironobu-san.

> MISTY1 free license is permitted for academic (non-profit) use. But it
> have been uncleared what academic (non-profit) is.  And There is no
> obvious definition of "academic", "non-profit" and "commercial".
> MISTY1 situation made me very confused.  I've thought that MISTY1 was
> the best choice in 1998 but legal issues was the worst.

Your understanding does not reflect the current situation.  Royalty-
free license of MISTY1 can be provided since the end of 1998.  MISTY1
can be used for both academic and commercial without paying the royalty
of the patent.
In fact, free license of academic is not a license.  Any patented
technology can be used if the patent holder does not suffer any damage.
Mitsubishi Electric Corporation ragards that this kind of usage has
no problem.
In the early 1998 (at the time that you implemented MISTY1), the royalty-
free license was not provided yet.  So, MISTY1 could not be used freely
except for academic use.
Now, royalty-free license exists.  But as some people point out, current
royalty-free license does not fit with RFC 2026, so that Mitsubishi
Electric Corporation is now reviewing the license.
New MISTY1 royalty-free license under reasonable and non-discriminatory
terms will be announced by the end of this year.

Regards
--
Hide.

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