Cryptography-Digest Digest #156, Volume #9 Sun, 28 Feb 99 02:13:03 EST
Contents:
--- sci.crypt charter: read before you post (weekly notice) (D. J. Bernstein)
Re: Can the quantum computer determine the truth from a lie? (wtshaw)
Off Topic (send me a copy of your comments) (BZ Consultants)
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (D. J. Bernstein)
Crossposted-To: talk.politics.crypto
Subject: --- sci.crypt charter: read before you post (weekly notice)
Date: 28 Feb 1999 06:00:37 GMT
sci.crypt Different methods of data en/decryption.
sci.crypt.research Cryptography, cryptanalysis, and related issues.
talk.politics.crypto The relation between cryptography and government.
The Cryptography FAQ is posted to sci.crypt and talk.politics.crypto
every three weeks. You should read it before posting to either group.
A common myth is that sci.crypt is USENET's catch-all crypto newsgroup.
It is not. It is reserved for discussion of the _science_ of cryptology,
including cryptography, cryptanalysis, and related topics such as
one-way hash functions.
Use talk.politics.crypto for the _politics_ of cryptography, including
Clipper, Digital Telephony, NSA, RSADSI, the distribution of RC4, and
export controls.
What if you want to post an article which is neither pure science nor
pure politics? Go for talk.politics.crypto. Political discussions are
naturally free-ranging, and can easily include scientific articles. But
sci.crypt is much more limited: it has no room for politics.
It's appropriate to post (or at least cross-post) Clipper discussions to
alt.privacy.clipper, which should become talk.politics.crypto.clipper at
some point.
There are now several PGP newsgroups. Try comp.security.pgp.resources if
you want to find PGP, c.s.pgp.tech if you want to set it up and use it,
and c.s.pgp.discuss for other PGP-related questions.
Questions about microfilm and smuggling and other non-cryptographic
``spy stuff'' don't belong in sci.crypt. Try alt.security.
Other relevant newsgroups: misc.legal.computing, comp.org.eff.talk,
comp.org.cpsr.talk, alt.politics.org.nsa, comp.patents, sci.math,
comp.compression, comp.security.misc.
Here's the sci.crypt.research charter: ``The discussion of cryptography,
cryptanalysis, and related issues, in a more civilised environment than
is currently provided by sci.crypt.'' If you want to submit something to
the moderators, try [EMAIL PROTECTED]
---Dan
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Crossposted-To: alt.privacy,talk.politics.crypto
Subject: Re: Can the quantum computer determine the truth from a lie?
Date: Sat, 27 Feb 1999 23:34:54 -0600
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] wrote:
>
> The idea that by inputting an encrypted message into a black box quantum
> computer and that it will absolutely output the correct encrypted
> message is preposterous.
>
It all depends on whether enough information is supplied whether a result
can be obtained. Most classic crypto does not take much ciphertext to
support finding a solution; quantum computers would cut quickly through
this level stuff as brute forcing is apt to be reasonable if no other
techniques are available.
The other two possibilities are that the ciphertext can be solved given
enough of it, or that it cannot be solved at all since you can never get
enough material to work on.
The amount of ciphertext required for the OTP for instance would be an
infinite amount. Anything else, something lesser.
The strength of interaction of algorithm, plaintext, and key determines
the absolute strength of the combination in terms of how much ciphertext
is required for solution. Shannon tried to pin down this same sort of
thing, but except for simple situations, getting the terms right is always
going to be elusive, and mathematically unpleasing.
Functionally, an empirical determination of strength is probably the best
that one can do: If insufficient ciphertext is available, look for more
using the same keys and the same algorithm until you solve or give up.
The skills of the attacker, or the programmer of an attacking program are
the key ingredients, for they will forever determine what to look for in
finding a solution, or in attempting a brute force attack if reasonable.
About telling the truth from a lie, computers only do what they are told,
it is people that chose between those alternatives. Insufficient evidence
is not a lie, truth is whole in any part; what is most likely false is
your expectation that you can always get what you want when you want it
from whoever you demand give it to you.
--
A much too common philosophy:
It's no fun to have power....unless you can abuse it.
------------------------------
From: BZ Consultants <[EMAIL PROTECTED]>
Crossposted-To: sci.math,sci.physics,sci.logic
Subject: Off Topic (send me a copy of your comments)
Date: Sun, 28 Feb 1999 01:40:31 -0800
Appreciate it if anyone posting on this topic can send me a copy
(E-mail address: [EMAIL PROTECTED]) Many thanks!!!
Thanks, Neil, for the wonderful comments.
=====================================================================
Neil Nelson wrote:
>
> In article <7b4ua7$1kc$[EMAIL PROTECTED]>,
>
> Many thanks to the well known mathematician G. J. Chaitin for
> providing web links to his recent viewpoints.
>
> G. J. Chaitin wrote
> (http://www.umcs.maine.edu/~chaitin/unknowable/):
>
> [ In a nutshell, Gödel discovered incompleteness, Turing discovered
> [ uncomputability, and I discovered randomness---that's the amazing
> ^^^^^^^^^^
???
> [ fact that some mathematical statements are true for no reason,
> ^^^^^^^^^^^^^^^^^^^^^^^^
???
> [ they're true by accident. There can be no ``theory of everything,''
> [ at least not in mathematics. Maybe in physics! ^^^^^^^^^^^^^^^^^^
>^^^^^^^^^^^^^^^^
New? How?
If this has never been said before, or not in a pretty definitive
manner, could someone expound a bit in layman's terms? How could it
be, and in 'exactly' what sense: not in mathematics but in physics?
>
> If these statements were true for no reason, it is not likely we would
> need Gödel's, Turing's, and Chaitin's detailed reasons, as evidenced
> in their papers, to convince us they were true. Chaitin's viewpoint
> conforms to the common Platonism in mathematics by presuming that
> proof is merely a confirmation of pre-existing truth, and that somehow
> the mentioned theorems evidence the Platonistic distinction in
> identifying truth without proof (true for no reason). However I
> suggest, whatever we know, we know by some means, and it seems a
> ^^^^^^^^^^^^^^
!!!
> rather arbitrary distinction to say the means in one case was a proof
> and in another was not. I.e., there can be no proof of the
> Platonistic distinction by definition and hence it becomes a
> metaphysical/philosophical assumption.
>
> Karl M. wrote:
>
> < After looking through your paper: The difference between MATTER
> < being paramount and INFORMATION being paramount is the difference
> < between
>
> < RANDOM=CHAOS/COMPLEXITY and
>
> < RANDOM=INFORMATION*COMPLEXITY.
>
> And the reference from Chaitin
> (http://www.umcs.maine.edu/~chaitin/unknowable/ch7.html)
> apparently being:
>
> [ The conventional view is that matter is primary, and that
> [ information, if it exists, emerges from matter. But what if
> [ information is primary, and matter is the secondary phenomenon!
>^^^^^^^^^^^^^^^^^^^^^^^^
Good point! But any different?
> [ After all, the same information can have many different material
> [ representations in biology, in physics, and in psychology: DNA, RNA;
> [ DVD's, videotapes; long-term memory, short-term memory, nerve
> [ impulses, hormones. The material representation is irrelevant, what
> [ counts is the information itself. The same software can run on many
> [ machines.
>
> Although the question of information vs. matter can be viewed in this
> way, it will be somewhat difficult to communicate the question without
> embedding the derived concept of matter in information for
> communication. I.e., if we are already in an information bounded
> context, it is ultimately self-defeating to speak of that which is not
> information.
>
> Although there is an assumed matter substrate to communication (that
> which carries the symbols of communication), it is the operations of
> forming and recognizing patterns in matter that is communication.
> Also information is assumed representational, to be about something
> other than the symbols, though perhaps this representational aspect
> can be exchanged for another operation of meaning. Hence information
> is at least twice removed, via pattern recognition as (1) symbol and
> (2) meaning, from particular physical instances of the communication
> substrate.
>
> Neil Nelson
>
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