Article View: sci.crypt
Article #1018Re: PEM question
From: Joseph F. Hull
Date: Wed, 07 Oct 1992 23:02
Date: Wed, 07 Oct 1992 23:02
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1911 bytes
Bob,
Your choice of words in this article runs a serious chance of confusing
the issue.
In article <BvL79M.8on@gpu.utcs.utoronto.ca>,
mirage1@gpu.utcs.utoronto.ca (Robert Ames) writes:
|> A number of people have replied to my question about the PEM protocol,
|> pointing out that even if the private key involved in one message
^^^^^^^^^^^
|> exchange were to be discovered, this would only have the effect of a
|> "known plaintext attack" on the RSA encryption used to exchange the
|> keys. In other words, the sender's private RSA would remain secure.
^^^^^^^^^^^
What you call a "private key" above should be called a "single message key"
to avoid any chance of someone else confusing it with the "private key"
part of a public key encryption system, what you call "private RSA" above.
A large part of PGP's strength is due to the fact that very limited amounts of
information are ever directly protected by a single key, i.e., only one
message is ever protected by the "single message key" and only the (very small
amount of information of the) "single message keys" transferred between
changes of "public key / private key" pairs is protected by those keys.
--
_ _
/_ / ) / ) Jeff Hull jhull@den.mmc.com
//_) -/- -/- 1544 S. Vaughn Cir
/_/ \_/ / / Aurora, CO 80012 303-977-1061
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<1992Oct7.230232.17530@den.mmc.com>Path:
arc1-ca.pugleaf.net!sparky!uunet!elroy.jpl.nasa.gov!ames!ncar!csn!news.den.mmc.com!thor!jhullReferences:
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Newsgroups: sci.crypt Path: arc1-ca.pugleaf.net!sparky!uunet!elroy.jpl.nasa.gov!ames!ncar!csn!news.den.mmc.com!thor!jhull From: jhull@thor.NoSubdomain.NoDomain ( Joseph F. Hull) Subject: Re: PEM question Message-ID: <1992Oct7.230232.17530@den.mmc.com> Keywords: RSA PEM Sender: jhull@thor ( Joseph F. Hull) Nntp-Posting-Host: thor.den.mmc.com Organization: Martin Marietta Astronautics, Denver References: <BvL79M.8on@gpu.utcs.utoronto.ca> Date: Wed, 7 Oct 1992 23:02:32 GMT Lines: 28