Cryptography-Digest Digest #992, Volume #9 Thu, 5 Aug 99 19:13:03 EDT
Contents:
ANSI standards? (Jonathan Katz)
challenges / competitions??? (Gabe Simon)
Re: Good generators and primes for Diffie Hellman (DJohn37050)
Re: What is "the best" file cryptography program out there? ([EMAIL PROTECTED])
Re: Transposition and substitution algorithms ??? (John Savard)
AES finalists to be announced ([EMAIL PROTECTED])
Re: Construction of permutation matrix ([EMAIL PROTECTED])
Re: AES finalists to be announced ([EMAIL PROTECTED])
Re: What is "the best" file cryptography program out there? (SCOTT19U.ZIP_GUY)
Re: Is the output of 3DES really pseudorandom??? ("karl malbrain")
Re: ANSI standards? (DJohn37050)
Re: What is "the best" file cryptography program out there? (SCOTT19U.ZIP_GUY)
Re: challenges / competitions??? (SCOTT19U.ZIP_GUY)
Re: challenges / competitions??? (DJohn37050)
Re: AES finalists to be announced (John Myre)
Re: AES finalists to be announced (DJohn37050)
Re: What is "the best" file cryptography program out there? (Jim Dunnett)
Re: Prime number. ("Douglas A. Gwyn")
Re: Software License Generation - Assistance Requested ("Douglas A. Gwyn")
Re: Blowfish x86 assembler ("Kasper Pedersen")
Re: AES finalists to be announced (SCOTT19U.ZIP_GUY)
Re: What is "the best" file cryptography program out there? (KidMo84)
Re: any literature about trusted unit? ("Douglas A. Gwyn")
Re: Transposition and substitution algorithms ??? (wtshaw)
Re: OTP export controlled? (wtshaw)
Need letter frequencies (LasombraXX)
Re: Americans abroad/Encryption rules? (wtshaw)
Re: Bad Test of Steve Reid's SHA1 (wtshaw)
Re: Americans abroad/Encryption rules? (wtshaw)
Re: frequency of prime numbers? (John McDonald, Jr.)
Re: Construction of permutation matrix (wtshaw)
Re: frequency of prime numbers? ("Douglas A. Gwyn")
----------------------------------------------------------------------------
From: Jonathan Katz <[EMAIL PROTECTED]>
Subject: ANSI standards?
Date: Thu, 5 Aug 1999 13:31:08 -0400
Is ANSI X9.52 available on-line anywhere? It describes modes of operation
for 3DES...
------------------------------
From: [EMAIL PROTECTED] (Gabe Simon)
Subject: challenges / competitions???
Date: 5 Aug 1999 17:58:45 GMT
=====BEGIN PGP SIGNED MESSAGE=====
Hash: SHA1
Hi,
I was just wondering if anyone knew about a website that had
cryptanalysis challenges for people to try to solve. I was hoping
for something with multiple levels of difficulty for us newbies out
there... If such a site does not exist... would anyone be interested
in making one? I know I would... it wouldn't be too hard to
organize...
Gabe Simon
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Version: PGPfreeware 6.5.1 for non-commercial use <http://www.pgp.com>
iQA/AwUBN6nQi578aT3Vj9DSEQIdpgCdHpKMe3WxK1LtzMNtCnPK390c/PIAnjrC
4f2809WM9yKjh8HLpkDQCv3E
=frQX
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------------------------------
From: [EMAIL PROTECTED] (DJohn37050)
Subject: Re: Good generators and primes for Diffie Hellman
Date: 05 Aug 1999 17:11:45 GMT
There are certain attacks that are often possible (sometimes called small
subgroup attacks) if the generator is not a generator of a large prime-order
subgroup. In this context, one usually wants the order to be a 160-bit prime
or larger.
Don Johnson
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: What is "the best" file cryptography program out there?
Date: Thu, 05 Aug 1999 17:22:44 GMT
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (KidMo84) wrote:
> You know, i always wonder what the NSA has broken but has not
released to the
> public yet:).
I will let you in a secret:
Cryptography is not only about keeping things secret!!!!
It's about authentication, privacy, identification, fraud prevention
etc...
Tom
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Transposition and substitution algorithms ???
Date: Thu, 05 Aug 1999 18:06:38 GMT
Spike Ivans <[EMAIL PROTECTED]> wrote, in part:
>However, in the manual, it states that all cryptographic
>systems rely on either or both of two techniques, transposition and
>substitution. So... having said that, I have a few questions...
>1) Is this true ?
Yes - inescapably and unavoidably. However, that is actually a very
interesting question even so.
About all you can do with a text, or a series of bits, to conceal it
is to replace some bits, or groups of bits, by other bits or groups of
bits - or move it to some other spot in the message.
That's what is unavoidable.
But it conceals the other things that may happen to make things
interesting.
a) You don't have to replace each byte by other bytes in the same way
throughout the message; the rule of substitution can change with each
byte.
b) Subsitution doesn't have to be done on single bytes; it can be
applied to larger blocks, such as blocks of eight bytes.
c) Transposition doesn't have to be done on whole bytes; it can be
applied to smaller units, such as individual bits.
And some modern cryptographic systems may use a non-invertible
substitution (like a hash function) on one part of a message to
determine which substitution rule to apply to another part of a
message. (For example, the f-function in DES is not invertible.)
>2) How do modern cryptographic systems implement transposition and
>substitution ?
In lots of different ways. My web site gives just a few.
John Savard ( teneerf<- )
http://www.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: [EMAIL PROTECTED]
Subject: AES finalists to be announced
Date: Thu, 05 Aug 1999 17:26:47 GMT
I have been informed by NIST that the five or so AES finalists will be
announced next Monday at 10 am. My Frog algorithm, as expected, will
not be one of them.
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Construction of permutation matrix
Date: Thu, 05 Aug 1999 17:35:43 GMT
In article <7o9cv1$[EMAIL PROTECTED]>,
"Kwong Chan" <[EMAIL PROTECTED]> wrote:
> I am looking for algorithms to construct a permutation matrix from a
random
> seed.
> For example:
>
> Seed Permutation
> 000 -> (0,1,2)
> 001 -> (2,0,1)
> :
> :
> 111 -> (1,2,0)
>
> Any suggestions are appreciated.
A 'complete' method would be this
1. Make two n element lists, one empty (P list), and one containing
all numbers from 0 to n-1 (S List)
2. for i = 0 to (n-1) do
3. t = log2(n - i) new bits from the key
4. P[i] = S[t]
5. remove S[t] from S and replace with last element of S
6. next i
If you can extract fractions of bits and have log2(n!) bits of key this
will be complete (all permutations are possible).
Tom
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: AES finalists to be announced
Date: Thu, 05 Aug 1999 17:38:52 GMT
In article <7ochg6$k7l$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
> I have been informed by NIST that the five or so AES finalists will be
> announced next Monday at 10 am. My Frog algorithm, as expected, will
> not be one of them.
Joy.
You know if you made the diffusion rate higher in FROG it would be
secure (a bit slow but secure). I think the actual frog algorithm is
kinda cute (keysetup is gross though).
Tom
--
PGP key is at:
'http://mypage.goplay.com/tomstdenis/key.pgp'.
Free PRNG C++ lib:
'http://mypage.goplay.com/tomstdenis/prng.html'.
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: What is "the best" file cryptography program out there?
Date: Thu, 05 Aug 1999 19:52:32 GMT
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] (KidMo84)
wrote:
>I just need a way to encrypt a bunch of programs easily. Sorta like pgpdisk
>does.
>
>Signed,
>KidMo
There are many ways to do but I think it may be best to compress the whole
set of fiiles together with something like PKZIP and then use scott16u or
scott19u on the resulting file.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE
http://www.jim.com/jamesd/Kong/scott19u.zip
http://members.xoom.com/ecil/index.htm
NOTE EMAIL address is for SPAMERS
------------------------------
Reply-To: "karl malbrain" <[EMAIL PROTECTED]>
From: "karl malbrain" <[EMAIL PROTECTED]>
Subject: Re: Is the output of 3DES really pseudorandom???
Date: Thu, 5 Aug 1999 11:24:17 -0700
fungus <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Alwyn Allan wrote:
> > > Answer: No statistical test can ever tell you if a number is
> > > random - you can't prove a negative.
> >
> > I can prove a negative. Here is a negative:
> >
> > 2 is not the largest prime.
> >
> > Here is my proof:
> >
> > 3 is prime.
> >
> > What's wrong with that?
>
>
> That's not what "proving a negative" means.
>
> Proving a negative is like proving that UFOs don't exist or that
> Astrology doesn't work. UFO nuts and astrologers rely on the
> fact that you can't disprove their theories to stay in business.
> The burden of proof should be on them, but you'll find them
> strangely reluctant to provide undisputable proof.
First, there's nothing wrong with your example that 2 is not the largest
prime.
Second, who says you can't disprove the theories of <<UFO nuts or
astrologers>>? You can proceed along exactly the same lines as <<2 is the
largest prime>> by breaking down theories to material components. That's
called engineering, where the <<proof is in the pudding>>. One deals with
nonsense by keeping it out. Karl M
------------------------------
From: [EMAIL PROTECTED] (DJohn37050)
Subject: Re: ANSI standards?
Date: 05 Aug 1999 18:48:57 GMT
Not online for free. It is available for purchase either softcopy or hard.
Don Johnson
------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: What is "the best" file cryptography program out there?
Date: Thu, 05 Aug 1999 19:56:29 GMT
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] (KidMo84)
wrote:
>You know, i always wonder what the NSA has broken but has not released to the
>public yet:).
>
>Signed,
>KidMo
I think is is a safe bet that most of the high praised programs are broken by
the NSA and that would include the NSA candidates. If one is truely concerned
you should use several methods in series. But if you do this be sure to use
methods that have no headers or change the file lenght. You can use my code
as one of the methods since it will not change the file length and if any one
bit of the file changes the whole file changes.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE
http://www.jim.com/jamesd/Kong/scott19u.zip
http://members.xoom.com/ecil/index.htm
NOTE EMAIL address is for SPAMERS
------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: challenges / competitions???
Date: Thu, 05 Aug 1999 19:47:43 GMT
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] (Gabe Simon) wrote:
>-----BEGIN PGP SIGNED MESSAGE-----
>Hash: SHA1
>
>Hi,
>I was just wondering if anyone knew about a website that had
>cryptanalysis challenges for people to try to solve. I was hoping
>for something with multiple levels of difficulty for us newbies out
>there... If such a site does not exist... would anyone be interested
>in making one? I know I would... it wouldn't be too hard to
>organize...
>
>Gabe Simon
>
>
>
Yes my site contains such challenges and there is one that
ends in Nov 11 for 1000 dollars is cost nothing to enter.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE
http://www.jim.com/jamesd/Kong/scott19u.zip
http://members.xoom.com/ecil/index.htm
NOTE EMAIL address is for SPAMERS
------------------------------
From: [EMAIL PROTECTED] (DJohn37050)
Subject: Re: challenges / competitions???
Date: 05 Aug 1999 18:50:02 GMT
There are the RSA and DES challenges from RSA Labs and the ECC challenge from
Certicom. These have money/prizes attached to the harder problems.
Don Johnson
------------------------------
From: John Myre <[EMAIL PROTECTED]>
Subject: Re: AES finalists to be announced
Date: Thu, 05 Aug 1999 13:42:09 -0600
[EMAIL PROTECTED] wrote:
> I have been informed by NIST that the five or so AES finalists will be
> announced next Monday at 10 am. My Frog algorithm, as expected, will
> not be one of them.
Condolences (even if expected).
I imagine NIST at least said thank you...
John M.
------------------------------
From: [EMAIL PROTECTED] (DJohn37050)
Subject: Re: AES finalists to be announced
Date: 05 Aug 1999 18:48:15 GMT
I expect the announcement to be made at Crypto '99.
Don Johnson
------------------------------
From: [EMAIL PROTECTED] (Jim Dunnett)
Subject: Re: What is "the best" file cryptography program out there?
Date: Thu, 05 Aug 1999 19:33:19 GMT
Reply-To: Jim Dunnett
On 05 Aug 1999 14:22:57 GMT, [EMAIL PROTECTED] (KidMo84) wrote:
>I just need a way to encrypt a bunch of programs easily. Sorta like pgpdisk
>does.
ScramDisk is a very easy to use, stable and secure system,
with a wide choice of cryptographic algorithms.
--
Regards, Jim. |Findhorn Community:
amadeus%netcomuk.co.uk | Developing EcoVillage
dynastic%cwcom.net | of about 350 people:
|
PGP Key: pgpkeys.mit.edu:11371 | http://www.gaia.org/findhorn/
------------------------------
From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: Prime number.
Date: Thu, 5 Aug 1999 19:56:43 GMT
Jerry Coffin wrote:
> Though it's provided by MS's compiler, __int64 isn't a
> standard part of C++. There's been quite a bit of discussion about
> adding "long long" as a type in C, with a minimum of 64 bits, but I'm
> not sure whether it'll end up in the standard or not (quite a few
> embedded vendors oppose it as too much work to implement).
There is no real doubt that C9x will specify a mandatory 64-bit
(minimum width) integer type in every conforming implementation.
We have maintained that part of the draft standard for years,
all the way to FDIS stage (now under weigh). The basic language
part of C9x specifies "long long (int)" but there is also a new
standard header, <stdint.h> (also <inttypes.h>, which has been
around for a while on many 64-bit platforms), that provides
functionally-oriented typedef names for types of various widths
through 64 bits, along with macros to facilitate their use.
The objections haven't been so much on the grounds of "too much
work", because the addition of 64-bit support is a lot less work
than the rest of the new C9x functionality, but rather a concern
that applications would necessarily get fatter even if the 64-bit
types weren't being used. A new portion of the C9x Rationale
addresses that issue.
------------------------------
From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: Software License Generation - Assistance Requested
Date: Thu, 5 Aug 1999 20:07:38 GMT
"Kirk E. Lieb" wrote:
> I am developing a WinNT sw product which requires a one-time licensing
> scheme, and I am looking for assistance in understanding existing
> products or libraries that would be useful.
FLEXlm is widely used on UNIX systems. I don't know whether a Windows/NT
version is available, but I would imagine so. One nice thing is that
the license server can be accessed via the network, so multiple users
can share the license(s). FLEXlm has a Web site somewhere, try a Web
search to find it.
------------------------------
From: "Kasper Pedersen" <[EMAIL PROTECTED]>
Subject: Re: Blowfish x86 assembler
Date: Thu, 5 Aug 1999 09:00:46 +0200
Paul Rubin <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
>
> The Pentium-1 ("P1") is a much less advanced processor than the K6 or
> P2/P3. The P1 is basically two 486 pipelines stapled together. It
> doesn't have out-of-order execution like the K6 or P2/P3. If the two
> P1 pipes both contend for a resource such as a register or cache line,
> or if a result is wanted that's not yet available, one or both pipes
> simply stall. So to write optimal P1 code, you have to write in very
> contorted ways to keep both pipes running. Code that's optimal on the
> P1 will probably be suboptimal on the P2 or K6, and possibly worse
> than just straightforwardly written code.
> The best I was able to do on the P1 was about 16 cycles/byte, IIRC.
You're right - my first slash-and-hack-it routine was 20-50% faster on
K6/P2/3 than the P1 version.
16 cycles/byte=8 per round is rather impressive, I think. Then there can't
be much to gain.
------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: AES finalists to be announced
Date: Thu, 05 Aug 1999 21:51:43 GMT
In article <[EMAIL PROTECTED]>, John Myre <[EMAIL PROTECTED]> wrote:
>
>[EMAIL PROTECTED] wrote:
>> I have been informed by NIST that the five or so AES finalists will be
>> announced next Monday at 10 am. My Frog algorithm, as expected, will
>> not be one of them.
>
>Condolences (even if expected).
>
>I imagine NIST at least said thank you...
>
>John M.
Maybe you needed a fishyer name for your method. Or better yet if you had
some buddies at the NSA they could have given you pointers that would have
kept it weak enough so they could break it and yet strong enough so the public
crypto people could not. It is a hard line to follow with out the right kind
of friends in the right places but it could be done. Gee I bet 2fish made it
to the next round.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE
http://www.jim.com/jamesd/Kong/scott19u.zip
http://members.xoom.com/ecil/index.htm
NOTE EMAIL address is for SPAMERS
------------------------------
From: [EMAIL PROTECTED] (KidMo84)
Subject: Re: What is "the best" file cryptography program out there?
Date: 05 Aug 1999 22:13:16 GMT
hehe, i think ur just ubsesed with YOUR program:).
Signed,
KidMo
------------------------------
From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: any literature about trusted unit?
Date: Thu, 5 Aug 1999 20:29:37 GMT
[EMAIL PROTECTED] wrote:
> There are many literatures about "trusted" systems. Is there any study
> about how to make today's computer "trusted" by adding a unit, say,
> smart card, online service, etc.
The degree of trust of existing systems can sometimes be increased by
such means, but to really produce a trustworthy system it has to be
designed that way from the outset, not with "security" added on as an
afterthought.
The DoD "rainbow" books are available somewhere on the Web; I saw them
there the other day, but don't recall just where.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Transposition and substitution algorithms ???
Date: Thu, 05 Aug 1999 15:17:13 -0600
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (John Savard) wrote:
> Spike Ivans <[EMAIL PROTECTED]> wrote, in part:
>
>
> About all you can do with a text, or a series of bits, to conceal it
> is to replace some bits, or groups of bits, by other bits or groups of
> bits - or move it to some other spot in the message.
>
> That's what is unavoidable.
With all due respect John, that is not all you can do it all. Otherwise,
how do you account for the things I do from, with, and to texts that can
have nothing to do with bits.
>
....
>
> And some modern cryptographic systems may use a non-invertible
> substitution (like a hash function) on one part of a message to
> determine which substitution rule to apply to another part of a
> message. (For example, the f-function in DES is not invertible.)
Again, if modern only speaks to a limited few means of encryption, your
definition of modern is wanting. There is no cap to processes in
encryption, and no way to define modern as in more than a temporal way.
With advances in computers, more and more means to do more and more
different things in crypto will emerge. Because they are unfamiliar will
not make them bad per se, and certainly can not give cause to classify
them as not modern because they are too new.
>
> >2) How do modern cryptographic systems implement transposition and
> >substitution ?
>
> In lots of different ways. My web site gives just a few.
>
> John Savard ( teneerf<- )
> http://www.ecn.ab.ca/~jsavard/crypto.htm
It is a very good site.
--
Sometimes you have to punt, and hope for the best.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Crossposted-To: talk.politics.crypto
Subject: Re: OTP export controlled?
Date: Thu, 05 Aug 1999 16:14:29 -0600
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
....
> The OTP system, as compared to DES/IDEA/skipjack/AES candidates,
> that cannot have any internal weakness, that could be exploited....
Yep, its weaknesses are all external, and vulnerable by simple means.
--
Sometimes you have to punt, and hope for the best.
------------------------------
From: [EMAIL PROTECTED] (LasombraXX)
Subject: Need letter frequencies
Date: 05 Aug 1999 21:33:56 GMT
Greetings!
Once upon a time I had a chart listing the approx. frequencies of each
letter in the the English language. Can anyone provide me with this info, or at
least point me to a site that has it? Thanks.
"A common mistake that people make when trying to design something completely
foolproof is to underestimate the ingenuity of complete fools."
-Douglas Adams
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Americans abroad/Encryption rules?
Date: Thu, 05 Aug 1999 15:54:07 -0600
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED]
(David C. Oshel) wrote:
>
> A code is just a map, such as C source -> compiler -> x86 machine code.
> Not even necessarily reversible, since you can disassemble x86 machine
> code to C source or Pascal source.
Didn't you mean CAN'T?
>
> You can represent binary numbers in a base 355 system, which you then
> represent in a base 113 system, which is a real kick when you store the
> output in a binary computer file -- one way to "expand" a file to disguise
> its length.
Simple expansion or compression does little to hide anything since it
might be easily reversed.
>
> Encryption is a special case of encoding, since it has a social purpose
> unrelated to the details of method.
>
I would see encoding as a subset of encryption since it depends on not
having the means obscure, low security, and using a fixed key for it to be
generally used.
Imagine taking UU ciphertext with simple substitution of output
set...well, several different ciphertext sets are already used: If the set
was transposed, or not in one of an common pattern, it would be difficult
to handle, but it would still have all the other characteristics of UU.
But, again, the method would surely be outside of the RFC.
--
Sometimes you have to punt, and hope for the best.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Bad Test of Steve Reid's SHA1
Date: Thu, 05 Aug 1999 15:34:51 -0600
In article <7oc6u9$bjt$[EMAIL PROTECTED]>, [EMAIL PROTECTED] wrote:
> > 00010203
> >
> > I.e. the first byte becomes the mistyping of the four, and the fourth
> > byte ends up as a the least significant. This is what's generally
> > referred to as big-endian ordering. By contrast, on a little-endian
> > machine, the first byte will end up as the least-significant byte of
> > the whole, and the fourth will end up as the most significant. I.e.
> > if you take the string above and simply cast a pointer to its
> > beginning as a pointer to long, you'll end up with 03020100 as your
> > number. Therefore, on a little-endian machine, you have to take the
> > inputs and swap them around to produce the right number.
> >
The truth of the matter is that software itself can be written either way,
or even mixed as I sometimes do, rather than having to depend on the
traits of a machine. But, I write the interpretive functions myself either
way as required, so I never see any problem.
--
Sometimes you have to punt, and hope for the best.
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Americans abroad/Encryption rules?
Date: Thu, 05 Aug 1999 15:43:00 -0600
In article <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] (JPeschel) wrote:
> >[EMAIL PROTECTED] (wtshaw) writes:
...
> >>
> >So, you suggest that the difference is whether the key can be kept secret,
> >large enough keyspace? Then there should be a lower threshold for
> >keyspaces that should be openly excluded from any regulation.
> >
> >And, take something like UUencode, declared not to be encryption despite
> >the suggestive name. There is no reason that a simple manipulation or two
> >might make an application that does UU non-standard. I maintain that all
> >coding is encryption in a broad sense.
>
> WT, someone wrote that ROT-13 didn't have a key, but it does,
> 13, Caesar's key was three.
>
> The security of a system should be within the key: K.'s principle.
>
> A lot of these classical ciphers have a huge keyspace, even a Caesar
> cipher. The size of the keyspace, though, of course is meaningless
> for a Caesar cipher's security. So I think the US government
> would not bother to prosecute anyone for, say, making classical ciphers
> available from a US web site. (Doesn't the ACA do that?) I think
> a regulation that tried to specifically spell out what was exempt
> would run into trouble mainly because people would try to find loopholes.
Obviously strength is more than keyspace, and it is a tough question to
quantify. How to quantify it is one worth pursuing, but some sort of
scaling, as I have before suggested, to evaluate different algorithms is
probably indicated.
A regulation that specifically spelled out which ciphers were weaker or
stronger would simply direct people to use the better ciphers, sort of
counterproductive to the whole idea of wanting people to ignorantly use
bad ciphers.
>
> I suppose you could call UUencoding a form of encryption in a broad
> sense. Still, if you were teaching a class on encryption, it might
> be better not to consider UUencoding and the like as a subset of
> encryption. Too confusing, I think.
>
That is my point, that there can be no clear line, if any at all, between
what is encryption and what is not.
--
Sometimes you have to punt, and hope for the best.
------------------------------
From: [EMAIL PROTECTED] (John McDonald, Jr.)
Subject: Re: frequency of prime numbers?
Date: Thu, 05 Aug 1999 21:26:27 GMT
On 4 Aug 99 15:15:17 MDT, sl3nf.cc@usu@edu (Sniggerfardimungus) wrote:
>I ask this question here not because it necessarily relates to cryptography,
>but to an interest of cryptographers, prime numbers; is there any reason to
>believe that there are either a finite or an infinite number of primes? Even
>better, is there any proof either way?
I believe, (and I could be mistaken) that this is addressed in a
rather lengthy proof by Goedel. He purports that mathematics is an
incomplete and infinite system.
One implication of his theorom suggests that even though the
concentration of primes becomes smaller the further fown the
numberline you go, that there are still infinitely many primes.
I think I still have the simplification of his proof from my Computer
Science course last year if anyone wants it. I will be happy to
expound on his proof also...
BTW: Another implication that I believe arose from his proof was that
not only are there an infinite number of primes, but there are also an
infinite number of twin primes. Twin primes are two primes that are
seperated by two. ie (3-5), (5-7), (11-13), (41-43)
Hope this helps.
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John K. McDonald, Jr. Alcatel, USA
[EMAIL PROTECTED]
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------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Construction of permutation matrix
Date: Thu, 05 Aug 1999 15:25:58 -0600
In article <[EMAIL PROTECTED]>, Mok-Kong Shen
<[EMAIL PROTECTED]> wrote:
> Mok-Kong Shen wrote:
> >
> > What you need are 2^n random permutations (n=3 above) of [0,1, ... n-1].
> > Use a PRNG to generate these. See Knuth's book, vol. 2.
> >
>
> Addendum:
>
> In the case n=3 one necessarily has duplicates, since there are
> only 6 different permutations. If n>3 one can have distinct
> permutations (simply check for duplicates), if desired.
>
Which means a binary means such as you suggest may not be the most
appropriate for the job at hand.
--
Sometimes you have to punt, and hope for the best.
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From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: frequency of prime numbers?
Date: Thu, 5 Aug 1999 20:16:05 GMT
John Savard wrote:
> Actually, you see, IF our previous list contained all the primes, then
> our new number would indeed, by not being divisible by any of them,
> satisfy the _definition_ of a prime number, not being divisible by any
> prime smaller than itself.
Exactly right. Bob S protested too quickly this time.
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