Cryptography-Digest Digest #82, Volume #14 Thu, 5 Apr 01 12:13:01 EDT
Contents:
Beginners guide to how encryption algorythms work? (Mouse)
Re: Newbie looking for texts about DES and Blowfish ("Latyr Jean-Luc FAYE")
Re: AES VS. DES ("Latyr Jean-Luc FAYE")
Re: AES VS. DES ("Tom St Denis")
Actually I hope that my ex-mother would commit suicide .... and reasons are ...
([EMAIL PROTECTED])
Re: PGP Private key cracking service ("Thomas J. Boschloo")
Dickson Polynomials? ("Tom St Denis")
Re: Beginners guide to how encryption algorythms work? ("John A. Malley")
Re: rc4 without sbox swapping/updating (Phil Carmody)
Re: Newbie looking for texts about DES and Blowfish ("John A. Malley")
WiSCy v.4.25 Scientific Calculator for real, copmlex and matrix
operation+Grapher+Unit converter (Win'9x,NT,ME,2000) ("Igor Evsikov")
Jews are assassinating people .. also setting bombs in Israel by themselves .....
([EMAIL PROTECTED])
are there people here who want to try to decypher my algo? ("aka!,")
Re: are there people here who want to try to decypher my algo? ("Scott Fluhrer")
Comment on SafeBoot's RC5 algorithm ("Simon Hunt")
Re: Compression-encryption with a key (Tim Tyler)
Re: A gift for cryptanalysts ("Scott Fluhrer")
Re: Fractal Compression (Tim Tyler)
----------------------------------------------------------------------------
From: Mouse <[EMAIL PROTECTED]>
Subject: Beginners guide to how encryption algorythms work?
Date: Thu, 5 Apr 2001 06:22:04 +0100
I'm looking for a site with fairly easy to understand explanations of how
the encryption works and some of the theory behind it, if possible
without too much higher math (I know some is inevitable).
------------------------------
From: "Latyr Jean-Luc FAYE" <[EMAIL PROTECTED]>
Subject: Re: Newbie looking for texts about DES and Blowfish
Date: Thu, 5 Apr 2001 13:01:51 +0100
I had done a few work on DES two weeks ago for college with as well an C
implementation.
You can find them at the following URL :
http://mi6.faye.cjb.net/art08/
I don't know if all the links are ok ! Let me know if any problems. I'll
fixed them
JLuc
--
---
Latyr Jean-Luc FAYE
http://faye.cjb.net
"John Stanford" <[EMAIL PROTECTED]> a �crit dans le message news:
[EMAIL PROTECTED]
> I'm new to cryptography. Can anyone tell me where I can find texts
> about how Blowfish and DES work? Thanks
>
------------------------------
From: "Latyr Jean-Luc FAYE" <[EMAIL PROTECTED]>
Subject: Re: AES VS. DES
Date: Thu, 5 Apr 2001 13:28:37 +0100
I've read stuff about linear cryptanalysis, differential cryptanalysis and
the weakness of DES with these methods.
What about AES ???
---
Latyr Jean-Luc FAYE
http://faye.cjb.net
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: AES VS. DES
Date: Thu, 05 Apr 2001 13:03:25 GMT
"Latyr Jean-Luc FAYE" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> I've read stuff about linear cryptanalysis, differential cryptanalysis and
> the weakness of DES with these methods.
> What about AES ???
Were you in a coma for 3 years?
There were a ton of AES papers flying around. Why not check the NIST AES
website. They should still be up.
And I wouldn't exactly call DES "Weak" against diff and linear attacks since
they still require an enormous amount of plaintexts. AFAIK they have never
been used on a real ciphertext otherthan inhouse linear attacks. The best
way to defeat DES is to brute force it's keyspace.
Tom
------------------------------
From: [EMAIL PROTECTED]
Crossposted-To: alt.security,comp.security,alt.2600
Subject: Actually I hope that my ex-mother would commit suicide .... and reasons are
...
Date: 5 Apr 2001 13:40:20 GMT
She (Eeva Nuora) stole 4000 USD from me in 1990 during the process of her
divorce from my father to finance her divorce. I am against any divorces and
due to the fact that she stole my moneys, she became criminal.
In addition, in January, 2000 she collaborated with the U.S. citizens, my
separated spouse (ex-spouse), the government of Finland and the U.S.A. in
their efforts to make me lose all my properties and funds during the divorce
process that was started by my ex-spouse in December, 1999. For some reasons,
she has always tried to hurt me.
She actually lies a lot. For years in Finland she told people that she had to
do things to fund me, although she never gave me any money, but gave funds to
my ex-sister and ex-brother, who have always received moneys. But this is the
way it was.
And then in the USA when I told my ex-US relatives that I did not want to have
any contacts with her, these U.S. citizens tried to make me to communicate
with this criminal person. The life has never been good.
Mutta antaa sen viikatemiehen kostaa teille jokaiselle jotka ovat hyokanneet
minua vastaan ja yrittaneet tappaa minua .... antaa vaan sen viikatemiehen
kostaa teille ....
http://www.scorps.com/sound/bth.ram
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------------------------------
From: "Thomas J. Boschloo" <[EMAIL PROTECTED]>
Crossposted-To: alt.security.pgp,comp.security.pgp.discuss
Subject: Re: PGP Private key cracking service
Date: Thu, 05 Apr 2001 15:14:51 +0200
Flakdaddy wrote:
>
> You should be directing your question to those crazy guys and gals over in
> alt.binaries.cracks, maybe they would be a little more receptive to your
> problem.
He is not talking about software cracks or 'creative programming'. Learn
some more about cracking and learn some more about crypto.
Thomas
--
Kittenbirds - You, me and Jesus: "I love your hair it's just so long"
My homepage <http://home.soneraplaza.nl/mw/prive/boschloo>
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Dickson Polynomials?
Date: Thu, 05 Apr 2001 14:02:15 GMT
I was reading Vaudenays papers on Decorrelation theory and he mentioned
Dickson polynomials to get higher d-wise decorrelation functions. I
understand that a d-wise decorrelation function must be a bijection formed
by a irreducible polynomial with d terms (If you can factor it then it's not
d-wise).
What is a Dickson Polynomial? My web search has not turned up anything
usefull...
--
Tom St Denis
---
http://tomstdenis.home.dhs.org
------------------------------
From: "John A. Malley" <[EMAIL PROTECTED]>
Subject: Re: Beginners guide to how encryption algorythms work?
Date: Thu, 05 Apr 2001 07:04:07 -0700
Mouse wrote:
>
> I'm looking for a site with fairly easy to understand explanations of how
> the encryption works and some of the theory behind it, if possible
> without too much higher math (I know some is inevitable).
John Savard and Terry Ritter each authored and maintain web sites on
cryptology that may fit your needs:
Mr. Savard's site is at
http://fn2.freenet.edmonton.ab.ca/~jsavard/crypto/jscrypt.htm
Mr. Ritter's site is at http://www.io.com/~ritter/
There's also an excellent web site explaining classical ciphers and
their cryptanalysis at
http://www.fortunecity.com/skyscraper/coding/379/lesson1.htm
Hope this helps,
John A. Malley
[EMAIL PROTECTED]
------------------------------
From: Phil Carmody <[EMAIL PROTECTED]>
Subject: Re: rc4 without sbox swapping/updating
Date: Thu, 05 Apr 2001 14:06:06 GMT
Ken Savage wrote:
I hate do disagree with you in an argument like this, but I do believe
that in order to counter arguments of apparent bogosity, we must ensure
our own arguments are non-bogus.
> For instance, consider the sequence:
>
> 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, ...
>
> From an information-theoretic sense, this sequence is completely
> predictable, thus it has zero entropy, zero information and thus
> is not a data source. It's a "modulo-4 counter initialized to zero".
I has a very small finite information content. In order to be rid of it
you need to define the starting point (0), the direction (+1) and the
modulus (4). It's kolmogorov complexity is "half a line" as measured in
my own units i.e not much. But not zero.
------------------------------
From: "John A. Malley" <[EMAIL PROTECTED]>
Subject: Re: Newbie looking for texts about DES and Blowfish
Date: Thu, 05 Apr 2001 07:09:32 -0700
John Stanford wrote:
>
> I'm new to cryptography. Can anyone tell me where I can find texts
> about how Blowfish and DES work? Thanks
For the DES consider ordering a copy of "The DES, An Extensive
Documentation and Evaluation" by Mikael J. Simovits, Aegean Park Press,
ISBN 0-89412-248-7.
It's available via Amazon.com or BN.com or direct from Aegean Park Press
at http://www.aegeanparkpress.com
John A. Malley
[EMAIL PROTECTED]
------------------------------
From: "Igor Evsikov" <[EMAIL PROTECTED]>
Subject: WiSCy v.4.25 Scientific Calculator for real, copmlex and matrix
operation+Grapher+Unit converter (Win'9x,NT,ME,2000)
Date: Thu, 5 Apr 2001 10:46:22 -0400
I have upload new version of WiSCy99 v.4.25 to ZDNet:
http://www.zdnet.com/downloads/stories/info/0,,000PUQ,.html
WiSCy99 (Windows Scientific Calculator + Grapher + Unit Converter) is a
comprehensive yet easy-to-use scientific calculator. Very thorough and
nicely designed, WiSCy is well documented and has a familiar and attractive
interface that makes it a pleasure to use. Features include support for
color graphs, integration, trigonomic functions, a variety of statistics
functions, a constants list that can be easily edited, unit conversions and
editor for custom units convertor, and lots more. You can even build and
edit lists of user variables and functions. All calculations are logged to a
"tape" that can be saved as text or printed. Graph plots can be also be
saved in one of three graphics formats.
Features List:
- Arithmetic and logical operators and functions
- Common functions such as exp, ln, sqrt, sqr, bnml etc.
- Common, trigonometric, hyperbolic complex functions
- Trigonometric, Hyperbolic functions
- Numerical Integration
- Equations can be solved
- Special functions (Gamma, Bessel's, Si, Ci, erf, erfc, Fresnel's)
- Statistic functions (Average, Standard deviation, Sum, Random,
Gauss random, statistical variance, etc )
- FOR-type loop
- if (...) then (...) else (...) function
- Tape of results
- Assistant and debug: error position fixed
- Plot f(X), Contour Plot f(X,Y), Color Shading f(X,Y),
real 3D-Plot f(X,Y), Derivative, Fit.
- Print results, graphics and print preview
- Save graphics to BMP, WMF, EMF formats
- Matrix Operations(A+B=C, A-B=C, A*B=C, inverse(A)=C,
Power(A,n)=C, det |A|=C[1.1], Solve A(X)=C)
- Decimal, Hexadecimal and Binary bases
- Fixed point, Scientific, Engineering and Sexagesimal notations
- Radian and Degree modes for trigonometric functions
- Precision: 10-12 significant digits.
- Range: _(3.4E-4392 to 1.1E+4392)
- 10 pre defined variables, user define variables
- User define functions
- 30 user defined constants (up to 16000), search and edit file
with constants.
- Stack for expressions (up to 16000)
- Stack for results (up to 16000)
- Unit Converter
- Custom unit convertor
- Evaluate expressions from file
- Simple tape calculator
Changes: Evaluate expressions from file, simple tape calculatur,
custom units convertor.
Igor Evsikov
[EMAIL PROTECTED]
------------------------------
From: [EMAIL PROTECTED]
Crossposted-To: alt.2600,alt.security,comp.security
Subject: Jews are assassinating people .. also setting bombs in Israel by themselves
.....
Date: 5 Apr 2001 14:49:09 GMT
Just another day I read that a Jew was throwing bombs in Israel .. actually a
woman ... then they try to blame Palestinians ...... it is their secret
covert operations ....
They also assassinate people ... this is criminal .... but I suppose if they
assassinate .. they they can be assassinated .. a fair deal ... well come to
the game of General ......
----- Posted via NewsOne.Net: Free (anonymous) Usenet News via the Web -----
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made through NewsOne.Net violate posting guidelines, email [EMAIL PROTECTED]
------------------------------
From: "aka!," <[EMAIL PROTECTED]>
Subject: are there people here who want to try to decypher my algo?
Date: Thu, 05 Apr 2001 17:14:20 +0200
not that i am any good but i had this idea and i'm wondering if this
would be dificult to solve.
aka!.,
------------------------------
From: "Scott Fluhrer" <[EMAIL PROTECTED]>
Subject: Re: are there people here who want to try to decypher my algo?
Date: Thu, 5 Apr 2001 09:21:25 -0700
aka!, <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> not that i am any good but i had this idea and i'm wondering if this
> would be dificult to solve.
Well, post the algorithm if you want, but here are some tips:
- Please post the algorithm, not some ciphertext. No one here is really
interested in spending the time to reconstruct the algorithm, unless the
algorithm is trivial (and hence, insecure).
- When you post the algorithm, specify it precisely. The best would be
formal mathematical notation, acceptable would be portable code (e.g. ANSI
C, Java, something like that). The goal is specify things thoroughly enough
that someone else can make an interoperable version based on your
description. Specifying details is important -- cryptanalysis is often
dependent on the details.
--
poncho
------------------------------
From: "Simon Hunt" <[EMAIL PROTECTED]>
Subject: Comment on SafeBoot's RC5 algorithm
Date: Thu, 5 Apr 2001 16:28:28 +0100
All (especially Tom!)
finally got around to replying on the message thread : RC5-SAFE? - SAFEBOOT
from 9th Sep last year. The quote re the speed was from an old document and
is a bit misleading.
The RC5 alg we use has to work in a pre-boot (no DOS even) environment, and
is a nice unlooped assembler version of RC5 with cipher-block-chaining based
on the sectors. The raw alg works at about 400MB/s (yes, 400 megabytes of
data per second) on a 1ghz athelon in W32. The pre-boot alg runs at about
40MB/s on the same machine. The 6MB/s figure was from a old 486/33 machine.
So in our product SafeBoot, you don't see any slowdown if you run a
performance benchmark on it - take my word for it or arrange an eval and try
it yourself. Yes, I am saying total hard drive encryption, at 1024 bit, with
no slowdown....
As for your other comments...
>You guessed wrong, but that's quite alright.
>My problem is that it says a 1024-bit key and only uses 12 rounds.
>Personally anything under 16 rounds is not a good idea, and you can't
>use 1024-bit keys with RC5, well you could, but I wouldn't.
>It doesn't seem like a well thought out use of RC5.
>Tom
you can use whatever key size you like with RC5! who told you otherwise?
1024 bits is a nice number (128 bytes) and is easy to handle. Why use short
keys if you don't have to?
the last comment, well - We've been thinking about and using RC5 for about
10 years now - so I guess that gives us a bit more experience and commercial
know-how than perhaps you on this matter :-)
I'll ignore your comment about not touching our product... as did 300,000
other users.
Simon.
CTO Control Break
------------------------------
From: Tim Tyler <[EMAIL PROTECTED]>
Subject: Re: Compression-encryption with a key
Reply-To: [EMAIL PROTECTED]
Date: Thu, 5 Apr 2001 15:26:06 GMT
Mok-Kong Shen <[EMAIL PROTECTED]> wrote:
: amateur wrote:
:> What I said is "simultaneously".
:> That does not mean compression then encryption.
:> At the same time you compress, you encrypt. [...]
:> Does that system exist?
:> That is my question.
: Yes. You can also rather tightly combine encryption with
: compression. [...] If you use Huffman (or adaptive Huffman)
: compression, the labeling of the tree is at your disposal.
"Huffman encryption" is a fine example of simultaneous
compression and encryption.
However, it has been argued in the past that on it's own, it's not very
strong, and an adaptive chosen-plaintexts attack (and probably
something much less sophisticated) will let you read the Huffman tree
out of the start of the file.
ISTM that the benefits of mixing compression and encryption together are
rather minimal. Certainly today it telescopes your choice of compression
algorithm and your choice of encryption algorithm down to practically
nothing.
Keying orthodox compression algorithms is unlikely to offer much strength
- and trying to compress during most conventional types of encryption
is plainly a dumb idea.
--
__________
|im |yler Try my latest game - it rockz - http://rockz.co.uk/
------------------------------
From: "Scott Fluhrer" <[EMAIL PROTECTED]>
Subject: Re: A gift for cryptanalysts
Date: Thu, 5 Apr 2001 09:32:42 -0700
Mark Wooding <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Scott Fluhrer <[EMAIL PROTECTED]> wrote:
>
> > However, by adapting the general idea, I believe I have found a
differential
> > over 15 rounds that exists with probability circa 2**-60.
>
> Good work. Thanks for saving me from astonishment. ;-)
Actually, I wouldn't just call the algorithm as "broken". This is the most
academic break imaginable (given full codebook, get distinguisher), and I'm
not too certain if it'll actually work. What's somewhat more interesting is
that the differential actually exists.
>
> Hmm. I *should* now give up and go back to my day job. But rather than
> throw in the towel, I'll try to rescue my bad idea...
>
> > Input delta 0x80000000 => Output delta 0x00008000 (probability 1)
> > Input delta 0x00008000 => Output delta 0x80000000 (probability 2**-15)
>
> D'oh! I'd sort of noticed that, but decided that the probability was too
> low. My fault for not actually doing the arithmetic!
>
> I first note that widening the block makes the differentials
> correspondingly improbable. For example, a 128-bit wide Gift has a
> similarly-structured differential with probability 2^{-120}. So I'll
> think about a generalized Gift with b-bit blocks.
Actually, given you always have a full code book, the differential always is
just barely possible after 15 rounds, independent of block size. Of course,
the "full code book" becomes much bigger as you increase b.
>
> Secondly, Gift is holding up much better than I expected!
>
> Anyway, on to the tweaking...
>
> Adding C rather than XORing would fix this good and proper. The carries
> in the addition will square the differential probabilities. This is a
> somewhat ugly patch, though. (I didn't want to use addition here,
> because it makes the cipher too +/*-linear. I still don't.)
I'd really worry about mod 2**16-1 cryptanalysis then. Adds would preserve
those differentials, as will the rotates, and the multiplies. The xors in
the Feistel structure might save you, but I'd want to think about it
carefully.
>
> The problem seems to be an unwanted symmetry caused by the rotation
> constant. What does changing it from b/4 (b being the block width in
> bits) to some arbitrary r do to the differentials?
One problem with that idea is that moving r from b/4 would appear to
decrease the amount of diffusion you get each round. However, tweaking r
slightly *might* be a good compromise, if what we have here is actually a
symmetry problem...
I don't have time to follow your analysis now, maybe tomorrow...
--
poncho
------------------------------
From: Tim Tyler <[EMAIL PROTECTED]>
Subject: Re: Fractal Compression
Reply-To: [EMAIL PROTECTED]
Date: Thu, 5 Apr 2001 15:36:40 GMT
Tom St Denis <[EMAIL PROTECTED]> wrote:
: Fractal compression takes advantage of self similiarities of an image in the
: spatial domain(s). By breaking an image into IFS's (can't remember what
: that stands for)
"Iterated Function System(s)".
A bit like any encryption algorithm, so some might say ;-)
See http://www.cosy.sbg.ac.at/rec/ifs/ or http://draves.org/flame/ for
some pretty ones.
--
__________
|im |yler Try my latest game - it rockz - http://rockz.co.uk/
------------------------------
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