Cryptography-Digest Digest #53, Volume #14 Sun, 1 Apr 01 05:13:00 EDT
Contents:
NEWS READER CRASHING (SCOTT19U.ZIP_GUY)
Re: conferences? (Benjamin Goldberg)
Re: conferences? ("Tom St Denis")
Re: NEWS READER CRASHING (John Savard)
Re: What is ideal substitution cipher? (John Savard)
Re: Learning to write encryption algorithms. (John Savard)
Re: What is ideal substitution cipher? (newbie)
Re: simple stream cipher (hehehe) (Benjamin Goldberg)
Re: simple stream cipher (hehehe) ("Tom St Denis")
efficient rabin signature? ("Tom St Denis")
Re: Idea - (LONG) ("Douglas A. Gwyn")
Re: What is ideal substitution cipher? ("Douglas A. Gwyn")
Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST OR
SEND - TIA! (Nemo psj)
Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST OR
SEND - TIA! ("Tom St Denis")
Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST OR
SEND - TIA! (Ben Cantrick)
Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST OR
SEND - TIA! ("Tom St Denis")
Re: What do we mean when we say a cipher is broken? (Paul Crowley)
Re: What do we mean when we say a cipher is broken? ("Tom St Denis")
AES VS. DES ("Latyr Jean-Luc FAYE")
encryption method used in MSPassport? (Matthew)
Re: AES VS. DES (SCOTT19U.ZIP_GUY)
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: NEWS READER CRASHING
Date: 1 Apr 2001 00:24:09 GMT
I have noticed that sometimes I get a message that flat crashes
my newsreader. I found it best to just not look at such messages
a second time becasue it is repeatable. I use Xnews read for now
but today I opened a message up and the next thing I new my browser
opened and was sending mail. I killed the connection but has this
happened to any one else. The post that caused the mail was in
another news group but it kind of surprised me.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE "OLD VERSIOM"
http://www.jim.com/jamesd/Kong/scott19u.zip
Scott famous encryption website **now all allowed**
http://members.nbci.com/ecil/index.htm
Scott LATEST UPDATED sources for scott*u.zip
http://radiusnet.net/crypto/archive/scott/
Scott famous Compression Page
http://members.nbci.com/ecil/compress.htm
**NOTE FOR EMAIL drop the roman "five" ***
A final thought from President Bill: "The road to tyranny,
we must never forget, begins with the destruction of the truth."
------------------------------
From: Benjamin Goldberg <[EMAIL PROTECTED]>
Subject: Re: conferences?
Date: Sun, 01 Apr 2001 00:46:52 GMT
Tom St Denis wrote:
[snip]
> The cipher is better in the encryption direction since the matrix
> [2 1] .. [1 1] is simple to implement... a multiplication of 2 is
> basically computed via
>
> if (x & 0x80)
> return (x << 1) ^ 0x69;
> else
> return x <<1;
>
> (C notation). I can even precompute this easily...
Which is faster, the above, or
return ((x&0x80) ? 0x69 : 0) ^ (x<<1);
I suspect that the latter might be faster, by virtue of using a
conditional assign, rather than a conditional branch.
Of course, a smart compiler might be able to optimize the first to the
second.
--
Sometimes the journey *is* its own reward--but not when you're trying to
get to the bathroom in time.
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: conferences?
Date: Sun, 01 Apr 2001 00:56:34 GMT
"Benjamin Goldberg" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Tom St Denis wrote:
> [snip]
> > The cipher is better in the encryption direction since the matrix
> > [2 1] .. [1 1] is simple to implement... a multiplication of 2 is
> > basically computed via
> >
> > if (x & 0x80)
> > return (x << 1) ^ 0x69;
> > else
> > return x <<1;
> >
> > (C notation). I can even precompute this easily...
>
> Which is faster, the above, or
> return ((x&0x80) ? 0x69 : 0) ^ (x<<1);
>
> I suspect that the latter might be faster, by virtue of using a
> conditional assign, rather than a conditional branch.
>
> Of course, a smart compiler might be able to optimize the first to the
> second.
Yours is probably faster, but that wasn't my point. I wanted to make the
code simple and easy to work with.
Tom
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: NEWS READER CRASHING
Date: Sun, 01 Apr 2001 00:59:33 GMT
On 1 Apr 2001 00:24:09 GMT, [EMAIL PROTECTED]
(SCOTT19U.ZIP_GUY) wrote, in part:
> I have noticed that sometimes I get a message that flat crashes
>my newsreader. I found it best to just not look at such messages
>a second time becasue it is repeatable. I use Xnews read for now
>but today I opened a message up and the next thing I new my browser
>opened and was sending mail. I killed the connection but has this
>happened to any one else. The post that caused the mail was in
>another news group but it kind of surprised me.
There was a malicious JavaScript posting in several newsgroups -
including this one. Some newsreaders, like Free Agent, don't try to
execute content from postings you view.
John Savard
http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: What is ideal substitution cipher?
Date: Sun, 01 Apr 2001 01:08:50 GMT
On Sat, 31 Mar 2001 13:59:45 -0400, newbie <[EMAIL PROTECTED]>
wrote, in part:
>Is ideal substitution cipher breakable?
>Is there a way to build it?
Well, because there isn't really an answer to the question in the
_title_ of the post,
What is ideal substitution cipher?
it's pretty hard for anyone to answer your other two questions.
Of course there is one cipher that is commonly thought of as the
perfect cipher, and it is a substitution cipher. It is known as the
one-time-pad.
This cipher is not breakable, and it can be put into practice.
The problem is that the key has to be as long as all the messages you
will send, and it has to be exchanged by direct physical contact in
advance. So it is possible to use it, it just isn't convenient enough
for most people.
John Savard
http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Learning to write encryption algorithms.
Date: Sun, 01 Apr 2001 01:03:18 GMT
On Sat, 31 Mar 2001 21:59:57 +0100, "m.wolfenden"
<[EMAIL PROTECTED]> wrote, in part:
>I would like to learn about how to write encryption algorithms to encrypt
>files. Does anyone know whether there are any online tutorials or online
>books or where I should go for help.
This may sound picky, but you don't write an algorithm.
You can design or invent an algorithm.
You can also _implement_ an algorithm by writing a _program_ that
carries it out.
Doing the latter requires knowing how to read and write files in
binary mode, and carry out arithmetic and bit manipulations. So
general books on programming will help you there. The main thing is
that the code has to be flawless, so you need a good set of
intermediate test vectors, and you have to be able to figure out what
could be the cause if you get an incorrect result.
John Savard
http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: newbie <[EMAIL PROTECTED]>
Subject: Re: What is ideal substitution cipher?
Date: Sat, 31 Mar 2001 20:28:44 -0400
Just another question.
If someone find, using a keyed-mathematical function, a way to create a
value-substitute to every plaintext's character, is it ideal
substitution?
Example :
I convert a message " If someone find, using a keyed-mathematical
function, a way to create a value-substitute to every plaintext's
character, is it ideal substitution?" to 23.45.28.46.78.79.12.13. etc...
without repeating any value.
Is it a perfect substitution?
The recipient has to use a symmetric-key to find easily every character
of the plain-text.
That system does not exist I suppose.
John Savard wrote:
>
> On Sat, 31 Mar 2001 13:59:45 -0400, newbie <[EMAIL PROTECTED]>
> wrote, in part:
>
> >Is ideal substitution cipher breakable?
> >Is there a way to build it?
>
> Well, because there isn't really an answer to the question in the
> _title_ of the post,
>
> What is ideal substitution cipher?
>
> it's pretty hard for anyone to answer your other two questions.
>
> Of course there is one cipher that is commonly thought of as the
> perfect cipher, and it is a substitution cipher. It is known as the
> one-time-pad.
>
> This cipher is not breakable, and it can be put into practice.
>
> The problem is that the key has to be as long as all the messages you
> will send, and it has to be exchanged by direct physical contact in
> advance. So it is possible to use it, it just isn't convenient enough
> for most people.
>
> John Savard
> http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: Benjamin Goldberg <[EMAIL PROTECTED]>
Subject: Re: simple stream cipher (hehehe)
Date: Sun, 01 Apr 2001 01:55:30 GMT
I'm just posting this to double-check my understanding of your cipher.
Would this be a decent C code approximation of your cipher?
const unsigned char sbox[256] = { ... };
union {
unsigned long long u64;
unsigned char[8] u8[8];
} key;
const unsigned long long poly = ( some maximal length lfsr poly );
unsigned char next() {
unsigned char r = 0, i;
key.u64 = (key.u64>>1) ^ ((key.u64&1) ? poly : 0);
for( i = 0; i < 8; ++i )
r = sbox[ key.u8[i] ^ r ];
return r;
}
Or am I clocking the LFSR in the wrong direction? I expect I am, but
this way is easier to write than &ing with 0x8000000000000000, ya know?
--
Sometimes the journey *is* its own reward--but not when you're trying to
get to the bathroom in time.
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: simple stream cipher (hehehe)
Date: Sun, 01 Apr 2001 02:01:11 GMT
"Benjamin Goldberg" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> I'm just posting this to double-check my understanding of your cipher.
>
> Would this be a decent C code approximation of your cipher?
>
> const unsigned char sbox[256] = { ... };
>
> union {
> unsigned long long u64;
> unsigned char[8] u8[8];
> } key;
>
> const unsigned long long poly = ( some maximal length lfsr poly );
>
> unsigned char next() {
> unsigned char r = 0, i;
> key.u64 = (key.u64>>1) ^ ((key.u64&1) ? poly : 0);
> for( i = 0; i < 8; ++i )
> r = sbox[ key.u8[i] ^ r ];
> return r;
> }
>
> Or am I clocking the LFSR in the wrong direction? I expect I am, but
> this way is easier to write than &ing with 0x8000000000000000, ya know?
That's about right, but I do clock it the other way (I might be doing it
wrong, I don't have my applied crypto...) Mainly I wrote my code for 8-bit
processors so I don't use long long ... (also this makes changing the size
of the key easier).
Any breaks?
Tom
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: efficient rabin signature?
Date: Sun, 01 Apr 2001 03:14:00 GMT
This has most likely been proposed before... but here is an idea I was just
thinking of..
The secret key is <p,q> which are two large primes (congruent to 3 mod 4)
such that N=pq is a blum integer. To sign a message you perform the
following.
1. K = (hash of message) * 65536
2. if J(N, K) = 1 then solve for the principal square root of K and store
it in M and goto step 4
3. If J(N, K) = -1 then increment the lower 16 bits of K and goto 2
3. Output M
To verify you simply do
1. K = M^2 mod N
2. Divide K by 65536
3. Compare K against the hash of the message.
Obviously some modifications can be made for example storing the lower 16
bits along with M such that they can be compared. Also modifying the upper
bits of K as (if) required.
--
Tom St Denis
---
http://tomstdenis.home.dhs.org
------------------------------
From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: Idea - (LONG)
Date: Sun, 01 Apr 2001 04:32:57 GMT
Mok-Kong Shen wrote:
> If one has r bits of truly random bits (never mind how to
> get this), one can only encrypt r bits with perfect
> security in the sense of Shannon.
Well, no, it depends on the source characteristics.
------------------------------
From: "Douglas A. Gwyn" <[EMAIL PROTECTED]>
Subject: Re: What is ideal substitution cipher?
Date: Sun, 01 Apr 2001 04:34:50 GMT
newbie wrote:
> If someone find, using a keyed-mathematical function, a way to create
> a value-substitute to every plaintext's character, is it ideal
> substitution?
No, that's just ordinary encryption.
------------------------------
From: [EMAIL PROTECTED] (Nemo psj)
Date: 01 Apr 2001 04:51:16 GMT
Subject: Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST
OR SEND - TIA!
It's Piracy the MCA makes everything piracy even if it's for educational
purposes... Welcome to corporate America :)
-Jay
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST
OR SEND - TIA!
Date: Sun, 01 Apr 2001 05:08:39 GMT
"Nemo psj" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> It's Piracy the MCA makes everything piracy even if it's for educational
> purposes... Welcome to corporate America :)
First of all it's the DMCA. And second of all copying a text digitally that
you don't own was illegal before DMCA, it's called piracy.
Solution, don't be a loser and just buy the text. And don't claim against
DMCA if you don't know what you are talking about. The problem with DMCA is
not that it prevents losers like you from pirating texts or movies, etc.
It's that it prevents free-use of materials (i.e as jokes, for teaching
...).
Tom
------------------------------
From: [EMAIL PROTECTED] (Ben Cantrick)
Subject: Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST
OR SEND - TIA!
Date: 31 Mar 2001 22:25:48 -0700
In article <[EMAIL PROTECTED]>,
Nemo psj <[EMAIL PROTECTED]> wrote:
>It's Piracy the MCA makes everything piracy even if it's for educational
>purposes... Welcome to corporate America :)
Even before the DCMA, it was only legal to *exerpt small portions* of
a copyrighted work for purposes of comment, criticism, education, etc...
not outright copy the whole thing.
I share your disgust for copyright laws, and the DCMA in particular,
but that still doesn't change the fact that Simon Singh went to a lot
of trouble and expense to write that book, and now you want to rob him.
Your position is not just wrong from a legal standpoint, it's wrong
from an ethical standpoint too.
-Ben
--
Ben Cantrick ([EMAIL PROTECTED]) | Yes, the AnimEigo BGC dubs still suck.
BGC Nukem: http://www.dim.com/~mackys/bgcnukem.html
The Spamdogs: http://www.dim.com/~mackys/spamdogs
"Technically, are women's birthday suits considered double-breasted?" -Willie B.
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: DOES ANYONE HAVE "THE CODE BOOK" BY SIMON SINGH IN PDF FORMAT? PLZ POST
OR SEND - TIA!
Date: Sun, 01 Apr 2001 05:27:31 GMT
"Ben Cantrick" <[EMAIL PROTECTED]> wrote in message
news:9a6e4s$[EMAIL PROTECTED]...
> In article <[EMAIL PROTECTED]>,
> Nemo psj <[EMAIL PROTECTED]> wrote:
> >It's Piracy the MCA makes everything piracy even if it's for educational
> >purposes... Welcome to corporate America :)
>
> I share your disgust for copyright laws, and the DCMA in particular,
> but that still doesn't change the fact that Simon Singh went to a lot
> of trouble and expense to write that book, and now you want to rob him.
The idea behind copyright law is a good one, the problem is who are they
trying to protect now. The citizens or coporations? However you're disgust
I think we all agree that copying materials as a whole is just mean and
wrong.
Tom
------------------------------
Subject: Re: What do we mean when we say a cipher is broken?
From: Paul Crowley <[EMAIL PROTECTED]>
Date: Sun, 01 Apr 2001 05:32:10 GMT
Paul Rubin <[EMAIL PROTECTED]> writes:
> But I thought Blowfish had a class of distinguishable keys (1/4096th
> of the keyspace or something like that).
A weakened variant, cut from 16 to 14 rounds, has this property.
--
__ Paul Crowley
\/ o\ [EMAIL PROTECTED]
/\__/ http://www.cluefactory.org.uk/paul/
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: What do we mean when we say a cipher is broken?
Date: Sun, 01 Apr 2001 05:50:51 GMT
"Paul Crowley" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Paul Rubin <[EMAIL PROTECTED]> writes:
> > But I thought Blowfish had a class of distinguishable keys (1/4096th
> > of the keyspace or something like that).
>
> A weakened variant, cut from 16 to 14 rounds, has this property.
And all you need is 6,755,399,441,055,744 plaintext/ciphertext pairs to
exploit it... what a shame really.
Tom
------------------------------
From: "Latyr Jean-Luc FAYE" <[EMAIL PROTECTED]>
Subject: AES VS. DES
Date: Sun, 1 Apr 2001 08:22:12 +0100
Hello,
It's the 2nd time I post this message.
I would like to know what are the difference between AES and its precursor
DES. What are the advantage of AES vs DES.
The first time, I got a nice answer of someone on the NG with a link to his
page about AES and I learnt lot of stuff.
But I lost the link. In fact I ma just hoping that anybody having a website
on AES or knowing a personnal website on AES will give me links. May be I
will find the one I lost.
Regards
---
Latyr Jean-Luc FAYE
http://faye.cjb.net
------------------------------
From: [EMAIL PROTECTED] (Matthew)
Subject: encryption method used in MSPassport?
Date: Sun, 01 Apr 2001 08:21:25 GMT
I drew the short straw at work and have to integrate a non ASP based
site with MS Passport. (our site is Java based, MS do not currently
provide a non ASP implementation, we are also trying the MS linux
implementation with jni ) So I'm currently looking at reverse
engineering the encryption / decryption process.
The MS documentation nominates 'triple DES', as the encryption
mechanism and registered users are provided with a single key that
looks something like this
KzijO6NLs92HT6obXNu1p38dS!AKB1Jm
(changed to protect the innocent, but this was a non production key
anyway)
the passport servers return a URL that contains encoded data ie.
1AAAAAAAAEkHTGjHOlu1vFD2akuiGr9UCGkpeNgAS9sh*3kVoJC6njeghER1R!cIxOqJN2ji3PY3NJz!2iLkJx9kPUS1rvmGVHQY*Yl1q8dYNYfNFagkxMtHBXP5MOFuK!rcLu8GeNHen*DWNLpAZXnFhEq5EnEGwKpM1iHhNniKo$
I tried using some sample java code (that uses the cryptix.org
package) to load the key, got error message - insufficient key length.
At the moment I'm trailling all the encryption - decryption mechanisms
I can get my hands on to get the hang of various processes. (ie
blowfish, DES, DES-EDE, RC2, Rijndael etc) when I get the hang of a
few of these I'll resume my reverse engineering process.
my main question is.
Am I remotely on the right track? (ie: has someone out there already
determined what process passport uses and how to implement it?)
I've been giving myself a crash course in this field, any pointers
appreciated.
Matthew.
PS: I'm not too happy about having to do this with passport, central
collation of peoples information tends to invite attacks. Besides I
prefer linux.
PPS: The basic mechanism of passport would not give a hacker access
unless they had the key to some site (by cracking or stealing the key)
, AND managed to intercept URL requests between a customer and the
passport server, OR a direct attack on the passport server itself.
------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: AES VS. DES
Date: 1 Apr 2001 08:15:35 GMT
[EMAIL PROTECTED] (Latyr Jean-Luc FAYE) wrote in
<[EMAIL PROTECTED]>:
>Hello,
>It's the 2nd time I post this message.
>I would like to know what are the difference between AES and its
>precursor DES. What are the advantage of AES vs DES.
>The first time, I got a nice answer of someone on the NG with a link to
>his page about AES and I learnt lot of stuff.
>But I lost the link. In fact I ma just hoping that anybody having a
>website on AES or knowing a personnal website on AES will give me links.
>May be I will find the one I lost.
>Regards
>
>---
>Latyr Jean-Luc FAYE
>http://faye.cjb.net
>
>
>
DES is the old US standard its known to be weak in that its not to
hard to break.
AES is the new standard which the US government wants you to use.
Telling you its totally safe. If might be safe as part of a larger
package. But by itself I would bet the NSA can break it or they
would not let it out. Since it will be in common use.
http://csrc.nist.gov/encryption/aes/
The best implimentation from a secruity point of view at this time
that I know of is Matt's BICOM I have a pointer at my site.
you could use his then run it through scott16u or scott19u as
a second pass for more security. Trust me mine is not like AES
or DES.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE "OLD VERSIOM"
http://www.jim.com/jamesd/Kong/scott19u.zip
Scott famous encryption website **now all allowed**
http://members.nbci.com/ecil/index.htm
Scott LATEST UPDATED sources for scott*u.zip
http://radiusnet.net/crypto/archive/scott/
Scott famous Compression Page
http://members.nbci.com/ecil/compress.htm
**NOTE FOR EMAIL drop the roman "five" ***
A final thought from President Bill: "The road to tyranny,
we must never forget, begins with the destruction of the truth."
------------------------------
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