[146750] in cryptography@c2.net mail archive
Re: [Cryptography] Why prefer symmetric crypto over public
daemon@ATHENA.MIT.EDU (Christian Huitema)
Sat Sep 7 16:12:22 2013
X-Original-To: cryptography@metzdowd.com
From: "Christian Huitema" <huitema@huitema.net>
To: "'Naif M. Otaibi'" <otaibinm@gmail.com>,
"'Jaap-Henk Hoepman'" <jhh@cs.ru.nl>
In-Reply-To: <CAC_smCkoZDEGviybZiHiMGMPBdGWXbwHv1J4JJ1eqD6peqf9-g@mail.gmail.com>
Date: Sat, 7 Sep 2013 12:25:35 -0700
Cc: 'Crypto' <cryptography@metzdowd.com>, 'Jon Callas' <jon@callas.org>
Errors-To: cryptography-bounces+crypto.discuss=bloom-picayune.mit.edu@metzdowd.com
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Another argument is =E2=80=9Cminimal dependency.=E2=80=9D If you use =
public key, you depend on both the public key algorithm, to establish =
the key, and the symmetric key algorithm, to protect the session. If you =
just use symmetric key, you depend on only one algorithm.
Of course, that means getting pair-wise shared secrets, and protecting =
them. Whether that=E2=80=99s harder or more fragile than maintaining a =
key ring is a matter of debate. It is probably more robust than relying =
on CA.
- -- Christian Huitema
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D'>Another argument is “minimal dependency.” If you use =
public key, you depend on both the public key algorithm, to establish =
the key, and the symmetric key algorithm, to protect the session. If you =
just use symmetric key, you depend on only one =
algorithm.<o:p></o:p></span></p><p class=3DMsoNormal><span =
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D'><o:p> </o:p></span></p><p class=3DMsoNormal><span =
style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497=
D'>Of course, that means getting pair-wise shared secrets, and =
protecting them. Whether that’s harder or more fragile than =
maintaining a key ring is a matter of debate. It is probably more robust =
than relying on CA.<o:p></o:p></span></p><p class=3DMsoNormal><span =
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D'><o:p> </o:p></span></p><p class=3DMsoNormal><span =
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D;mso-ligatures:standard'>-- Christian Huitema<o:p></o:p></span></p><p =
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