Cryptography-Digest Digest #594, Volume #12 Sat, 2 Sep 00 02:13:02 EDT
Contents:
New cryption method... (PROdotes)
Re: Quick, simple and easy cipher? (John Bailey)
Re: cryptology software ("Stou Sandalski")
Re: New cryption method... ("Stou Sandalski")
Re: Quick, simple and easy cipher? (wtshaw)
Re: Question Regarding Encrypting CD-ROM -RW Disks (Matthew Skala)
Re: 4x4 s-boxes (Terry Ritter)
Re: Capability of memorizing passwords (Thomas Wu)
Re: New cryption method... (S. T. L.)
----------------------------------------------------------------------------
From: PROdotes <[EMAIL PROTECTED]>
Subject: New cryption method...
Date: Sat, 2 Sep 2000 03:00:54 -0700
I think I've found an cryption method that could be very hard to break.
I've don some theoretic research today and tryed in on the computer (whit
some hardware restirctions) but the method could crypt an cca. 120
character string in more then 10^449 ways... and the larger the text the
larger the number of combinations. For now it's just in the test phase
but with some more modifications on the code and a better machine I think
it would theoreticly be very hard to break it even using an
supercomputer... and if the sourcecode would be unknown it would be
practicly impossible. I think I could even get the number up to 10^570
for the 120 chr. string.
The only problem is that the output is 2-3 times as large as the input...
------------------------------
From: [EMAIL PROTECTED] (John Bailey)
Subject: Re: Quick, simple and easy cipher?
Date: Sat, 02 Sep 2000 01:38:16 GMT
On Fri, 1 Sep 2000 21:36:05 +0100, "James Blythe"
<[EMAIL PROTECTED]> wrote:
>I'm looking for a pen, paper and calculator cipher that is quick and easy to
>understand, and could possibly have the advantage of being simulated on a
>computer. Solitaire and other such long-winded systems are great but I don't
>need that level of security and they take too long. I've developed my own
>system using simple multiplication of integers to create a keystream, but
>it's so simple I think I must be missing something and it's probably
>completely useless. Does anyone know of a system?
This may do what you want.
This is a public key method which essentially follows from published
work on knapsack based public key encryption however I
have not seen it presented in this form. To that extent then, the
following is original with me.
I found it useful as a functional example of public key cryptography
which was not quite as dismally trivial as examples of RSA
using small primes.
The idea is that a sender wants to transmit his credit card number x
to a vendor. The vendor provides the sender with two
numbers a and b. The sender multiplies his credit card number by a ,
selects a random number of perhaps 15 digits, multiplies that
number by b, adds the two and transmits this result (z) to the vendor.
The vendor knows two private key numbers c and d which he had used to
generate a and b. The vendor multiplies z by c,
subtracts d from the results repeatedly to generate cz mod d and then
repeats this process using the modulus e. Where e = bc mod
d.
The result is the credit card number, originally concealed by the
sender.
The math:
z = ax + by
cz = acx + bcy
if ac = 1 mod d
and bc = e mod d
then x = cz mod d mod e
The set-up:
In setting up the public key arrangement, values of
c, d, and e are chosen and kept secret. They are
used to calculate a and b and will be used later to
invert the encryption of x.
Values for a and b are published. To encode a value x, a number y is
picked at random. Using x and y in the equation z = ax + by,
the value of z becomes the encrypted message, corresponding to x.
Any receiver who knows c, d, and e can determine x by
using the relationship: x = cz mod d mod e.
Anyone knowing z, a and b can only determine x by
analysis.
Let me know what you think
John
------------------------------
From: "Stou Sandalski" <tangui [EMAIL PROTECTED]>
Subject: Re: cryptology software
Date: Fri, 1 Sep 2000 19:04:58 -0700
Maple is a symbolic algebra package... it might have some use in crypto...
but thats not what it was originaly designed to do... (as far as I know)
stou
"Michal Kvasnicka" <[EMAIL PROTECTED]> wrote in message
news:8onp7k$ull$[EMAIL PROTECTED]...
> I am looking for Maple or Matlab cryptography and cryptoanalysis software.
>
> Thanks in advance for any help,
>
> Michal
>
>
> --
> Michal Kvasnicka
> [EMAIL PROTECTED]
>
------------------------------
From: "Stou Sandalski" <tangui [EMAIL PROTECTED]>
Subject: Re: New cryption method...
Date: Fri, 1 Sep 2000 19:16:00 -0700
Last night after about 4 bowls of purple kush I invented a crypto method for
scrambling data that was theoreticaly unbreakable even with a quantum
computer... and not only did it encrypt data 10^31337 different ways, it
compressed the data 100 to 1.... but the NSA kidnaped me and forced me to
give them my algorithm and then brainwashed me and took off all evidence of
it... and then they drugged me... and when I woke up I couldn't remember
what the algorithm was... but it was really cool and unbreakable....
their is no such thing as.... "theoreticaly very hard..."... because "very
hard" is an opinion.... for my dog its very hard to change the chanels on
the TV... for me its easy... get it? Post some code and explanations or
refrain from increasing the noise to signal ration....
Stou
"PROdotes" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> I think I've found an cryption method that could be very hard to break.
> I've don some theoretic research today and tryed in on the computer (whit
> some hardware restirctions) but the method could crypt an cca. 120
> character string in more then 10^449 ways... and the larger the text the
> larger the number of combinations. For now it's just in the test phase
> but with some more modifications on the code and a better machine I think
> it would theoreticly be very hard to break it even using an
> supercomputer... and if the sourcecode would be unknown it would be
> practicly impossible. I think I could even get the number up to 10^570
> for the 120 chr. string.
> The only problem is that the output is 2-3 times as large as the input...
------------------------------
From: [EMAIL PROTECTED] (wtshaw)
Subject: Re: Quick, simple and easy cipher?
Date: Fri, 01 Sep 2000 19:42:25 -0600
In article <8op3s4$kkt$[EMAIL PROTECTED]>, "James Blythe"
<[EMAIL PROTECTED]> wrote:
> I'm looking for a pen, paper and calculator cipher that is quick and easy to
> understand, and could possibly have the advantage of being simulated on a
> computer. Solitaire and other such long-winded systems are great but I don't
> need that level of security and they take too long. I've developed my own
> system using simple multiplication of integers to create a keystream, but
> it's so simple I think I must be missing something and it's probably
> completely useless. Does anyone know of a system?
>
> Regards,
>
> James Blythe
Next question is whether you care that the cipher is easily solved with
sufficient attention. Depending, there are tons of possibilities.
--
A Pangram:
Exquisite jewels' good key facits bedazzel private humans.
------------------------------
From: [EMAIL PROTECTED] (Matthew Skala)
Subject: Re: Question Regarding Encrypting CD-ROM -RW Disks
Date: 1 Sep 2000 19:47:04 -0700
In article <8oo02r$[EMAIL PROTECTED]>,
Guy Macon <[EMAIL PROTECTED]> wrote:
>Water, and large quantities of sooty black smoke. The smoke contains a
>lot of Carbon and a fair amount of organic compounds, including Phenol,
Thanks for the information. This thread was originally about
*microwaving* CDs rather than burning them entirely. Microwaved CDs still
look like CDs, with the (fragmented) foil layer visible inside. That
suggests to me that very little of the plastic is actually burnt.
--
Matthew Skala
[EMAIL PROTECTED] I'm recording the boycott industry!
http://www.islandnet.com/~mskala/
------------------------------
From: [EMAIL PROTECTED] (Terry Ritter)
Subject: Re: 4x4 s-boxes
Date: Sat, 02 Sep 2000 03:57:57 GMT
On Fri, 01 Sep 2000 18:10:46 -0400, in <[EMAIL PROTECTED]>,
in sci.crypt "Douglas A. Gwyn" <[EMAIL PROTECTED]> wrote:
>Terry Ritter wrote:
>> While the FT originally defined "bent," most modern treatments use
>> the FWT.
>
>? What does the definition of bent function look like in terms
>of Walsh transforms? Is it as simple as the FT version? Keep in
>mind that it has to single out precisely the same family.
We could look it up, but it is my understanding that they are
essentially the same. I don't recall ever seeing a definitive paper
which showed the same results with both transforms, but at some point
in time everybody just switched.
>> As far as I know, in modern open cryptography, these concepts
>> [maximal nonlinearity and uniform Fourier weights] are the same.
>
>They can't be the same, because the latter defines a bent function
>but you guys are claiming that bent functions aren't maximally
>nonlinear.
You mistake the argument: I (who can only speak for myself) claim
that an s-box which is balanced cannot have full bent structure.
Alternately, if we fill an s-box with a bent function, we may have
good nonlinearity, but we will not have balance. And balance is
generally the most important part of a good s-box design.
>The reason the FT property is important is that it says there is
>no distinctive "bulge" in the distribution.
Right. I would say that the ideal or "maximally nonlinear" function
has the same distance from every applicable "affine" function.
>Bulges are exploitable,
>although so far as I know there is no open publication explaining
>how -- the nearest I've seen are some papers from Seberry's crowd.
I think there has been work on exploiting functions which may be
expressible as linear functions with errors, the linearity allowing
manipulation which would otherwise be unavailable.
But if there is substantial nonlinearity or distance from affine
functions (say, 80 bits), I personally am unaware of any exploitable
advantage accruing from knowing that the nonlinear function is a few
bits closer to one particular affine function than the rest. To me
that means that finding an "optimal" design is far, far more important
for small boxes than large ones. And in large boxes, strong -- albeit
non-optimal -- nonlinearity generally falls out of even random
construction.
---
Terry Ritter [EMAIL PROTECTED] http://www.io.com/~ritter/
Crypto Glossary http://www.io.com/~ritter/GLOSSARY.HTM
------------------------------
From: Thomas Wu <[EMAIL PROTECTED]>
Subject: Re: Capability of memorizing passwords
Date: 01 Sep 2000 20:58:29 -0700
Mok-Kong Shen <[EMAIL PROTECTED]> writes:
> [EMAIL PROTECTED] wrote:
> >
> > Human memory is very poorly understood, and in my experience, differs
> > greatly from person to person. I would expect the average to be much
> > lower than that.
>
> No question about that. But 8 ASCII characters amount
> to 56 bits only and we have them in readable character
> format that should facilitate memorizing.
>
> M. K. Shen
It's easy enough to memorize impressively long strings of characters,
or even word sequences, as some others have suggested, under laboratory
conditions. But in the real world, could most people do this for several
dozen Web sites at the same time? Could they generate and memorize this
password in the five minutes or so that they had to visit the average site?
Would they still remember it when they came back to the site six months
later? The last thing we want to do is increase the number of "I forgot
my password" support phone calls, and fancy password generation schemes
seem to have a knack for doing just that.
--
Tom Wu * finger -l [EMAIL PROTECTED] for PGP key *
E-mail: [EMAIL PROTECTED] "Those who would give up their freedoms in
Phone: (650) 723-1565 exchange for security deserve neither."
http://www-cs-students.stanford.edu/~tjw/ http://srp.stanford.edu/srp/
------------------------------
From: [EMAIL PROTECTED] (S. T. L.)
Date: 02 Sep 2000 05:21:52 GMT
Subject: Re: New cryption method...
/*I think I've found an cryption method that could be very hard to break.
I've don some theoretic research*/
I wouldn't trust an encryption method invented by someone who couldn't spell
"done" properly, let alone "encryption". "Done" might have been a typo, but
you mispelled "encryption" twice, and even in the subject line of the post!
Heh.
-*---*-------
S.T.L. My Quotes Page * http://quote.cjb.net * leads to my NEW site.
My upgraded Book Reviews Page: * http://sciencebook.cjb.net *
Optimized pngcrush executable now on my Download page!
Long live pngcrush! :->
------------------------------
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