Cryptography-Digest Digest #195, Volume #14 Fri, 20 Apr 01 22:13:01 EDT
Contents:
Re: OTP breaking strategy (newbie)
A Poem on Proper Communications (Frank Gerlach)
An die Deutsche Bundespost (F-104G Data Fighter)
Another Prayer (F-104G Data Fighter)
Re: Prime Numbers Patterns? What Base is best ("Wizartar")
GCHQ Reorganization ? (F-104G Data Fighter)
Re: Prime Numbers Patterns? What Base is best ("Tom St Denis")
Re: Random and not random (John Savard)
Solectron To Invest Into Technologies adapted from Black Holes (F-104G Data Fighter)
Re: LFSR Security ("Scott Fluhrer")
Re: First cipher ("Scott Fluhrer")
Re: Basic AES question ("Scott Fluhrer")
Re: Will this defeat keyloggers ? (Nemo psj)
Re: "UNCOBER" = Universal Code Breaker (newbie)
Re: "UNCOBER" = Universal Code Breaker ("Tom St Denis")
Re: "UNCOBER" = Universal Code Breaker (newbie)
Re: "UNCOBER" = Universal Code Breaker (newbie)
Re: "UNCOBER" = Universal Code Breaker ("Tom St Denis")
----------------------------------------------------------------------------
From: newbie <[EMAIL PROTECTED]>
Subject: Re: OTP breaking strategy
Date: Fri, 20 Apr 2001 20:11:29 -0300
Your article is nothing more than a duplicata of Jendal and cie.
Do not try please to deny it.
If you are so sure post the two texts at the same time to let others
appreciate if it is not duplicata.
I know that I'm newbie. I recognize that I have more to learn. I'm just
discovering what cryptography is. I learn more posting and reading posts
than reading books.
I was wrong on my try to propose a strategy because I under-estimate the
probability that any bit-string should be truly random.
If I could distinguish between two bit-string with high probability my
strategy could work.
That was not the case.
Mok-Kong Shen wrote:
>
> newbie wrote:
> >
> > Yuo have yet a plagiat's Nobel Prize. Did you read the article about
> > Ideal homophonic system?
>
> Take a mirror and look into it. I wrote an article with
> a content that is o.k. Nobody of the group has commented
> on that article at that time and evem if it turns out to
> duplicate someone else's stuff (I have not yet checked
> that fully, becase one paper is not yet available to me),
> it does not contain anything wrong.
>
> What do you do? You ignore other's hints to look into
> literatures where it is explained that OTP cannot be
> broken and stubbornly continue to claim the opposite. It
> certainly could not be excluded from the beginning that
> you might find something revolutionary. But you have at
> least first to read and study the existing literature and
> show that what is wrong there before putting up your
> claim that OTP could be broken. Just ignoring these
> existing knowldeges and nevertheless putting up your
> claims is wasting the bandwidth of this group. How many
> people have already patiently and gently give you the
> advice to read a bit the existing stuffs (one person
> even gives literature pointers in French) and learn a
> mininum from that, at least some common terminology
> to facilitate discussions, before continuing to post in
> your style?
>
> M. K. Shen
------------------------------
From: Frank Gerlach <[EMAIL PROTECTED]>
Subject: A Poem on Proper Communications
Date: Sat, 21 Apr 2001 02:12:01 +0200
Dear Almighty God,
I am an F-104G Data-Fighter,
I am sorry that I abused Secret Compartmentalized Information.
------------------------------
From: F-104G Data Fighter <[EMAIL PROTECTED]>
Subject: An die Deutsche Bundespost
Date: Sat, 21 Apr 2001 02:17:45 +0200
Es tut mir leid, dass ich nicht lizensierte Langstrecken-Empf�nger
einsetz(t)e.
------------------------------
From: F-104G Data Fighter <[EMAIL PROTECTED]>
Subject: Another Prayer
Date: Sat, 21 Apr 2001 02:14:53 +0200
Almighty God,
I am sorry that I have mixed up the powers of wind with the powers of
lyrics and mystics.
Please communicate my regret to all the people these powers belong to.
------------------------------
From: "Wizartar" <[EMAIL PROTECTED]>
Subject: Re: Prime Numbers Patterns? What Base is best
Date: Sat, 21 Apr 2001 01:31:07 +0100
Thanks all for the input,
So what people have said is, looking at prime numbers from base 10 is just
one point of view. As primes are external to the system you use to count
in.
The logical questions is.... What base has the most of these properties?
Is one base better then another when searching for prime numbers? Or does
base even come into play?
Again all input in of great help,
Wiz.
"Wizartar" <[EMAIL PROTECTED]> wrote in message
news:supD6.9627$[EMAIL PROTECTED]...
> Hi,
>
> Is there any logic to prime numbers, I've been doing a study of them for a
> computer course and still have a long way to good before I get a paper
> together.
>
> For an example of what I mean:
> All numbers ending in 0, 2, 4, 5, 6, 8, once you get above 9 are defiantly
> not a prime numbers. So only numbers ending in 1, 3, 7, 9 need to be
> tested. Are there any other common patterns, once you reach higher
numbers?
>
> Any help would be useful,
> Wiz
>
>
>
>
------------------------------
From: F-104G Data Fighter <[EMAIL PROTECTED]>
Subject: GCHQ Reorganization ?
Date: Sat, 21 Apr 2001 02:40:32 +0200
On my long-distance receiver I just intercepted the following
information:
GCHQ will be reorganized into
-Acoustic Intelligence Gathering (AIG), including the frequency-domain
analysis of hitting the keyboard
-Image Warping Technologies (aka OS-X)
-Spatzen-Gehirn Sezierung
-Spiegelstrich Graph-Analyse
-Strategische Propaganda
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: Prime Numbers Patterns? What Base is best
Date: Sat, 21 Apr 2001 00:59:19 GMT
"Wizartar" <[EMAIL PROTECTED]> wrote in message
news:Jy4E6.10283$[EMAIL PROTECTED]...
> Thanks all for the input,
>
> So what people have said is, looking at prime numbers from base 10 is just
> one point of view. As primes are external to the system you use to count
> in.
>
> The logical questions is.... What base has the most of these properties?
> Is one base better then another when searching for prime numbers? Or does
> base even come into play?
I doubt the base will tell you anything. In base 2, all numbers ending with
0 are not prime, in base 4 it's 0, 2, in base 10 it's 0,2,4,6,8, etc..
(except for 2 in base 10).
Tom
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Random and not random
Date: Sat, 21 Apr 2001 01:01:03 GMT
On 20 Apr 2001 16:39:43 -0700, [EMAIL PROTECTED] (Matthew
Skala) wrote, in part:
>The take-home lesson: the risk of possibly choosing a bad pad that reveals
>your message is *inextricably* linked to the perfect secrecy property.
>You can't have perfect secrecy without that risk, and any attempt to
>eliminate it will either fail or destroy the perfect secrecy property.
I know. This is why I propose to *keep* the perfect secrecy property,
by having the UOTP stage.
Naturally, the combination cipher - say DES, COTP, DES, UOTP, DES
could possibly result in a scrambled ciphertext that resembles the
original plaintext, since the UOTP might have any value, including the
value which would give that result.
The use of the COTP is indeed more to make people feel warm and fuzzy
than to truly make that possibility unlikely. In any case, a cipher
message that appears to be plaintext - but which came through three
conventional cipher stages - would presumably be less likely to be
read _as_ plaintext than such a message that would have resulted by
the simple application of a single OTP.
In other words, if we make our cipher machines big and noisy enough,
the enemy will come to believe that we actually are enciphering our
messages, and if one looks like plaintext, the enemy will not infer
anything from it.
Another way to look at it is to think of the cipher machine design as
having to have been approved by a bureaucracy, not all of whose
members are technically literate.
So we have General Jones, who insists that one-time-pads be checked
before use, because one that is all zeroes, all ones, or which
corresponds to a simple LFSR output will give away the message it is
used on;
but we also have Dr. Smith, who is familiar with the theory behind the
OTP, and notes that only when every possible pad can be used will the
mathematical property of total secrecy be achieved;
and then we have Mr. Robinson, who feels that all these big and bulky
one-time-pads are hard to shuffle around secretly, and if they just
get added to the secret message, then if someone manages to snap a
photograph of the OTP contents while they're being shipped, they won't
have much problem decoding the message, so something with a key easier
to hide ought to be used.
The system which I propose satisfies all three gentlemen!
Of course it is "overkill", but this kind of defense in depth does
make sense in the "real world", where key material sometimes does get
compromised.
John Savard
http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: F-104G Data Fighter <[EMAIL PROTECTED]>
Subject: Solectron To Invest Into Technologies adapted from Black Holes
Date: Sat, 21 Apr 2001 03:04:49 +0200
just got that from www.daeder�.com
------------------------------
From: "Scott Fluhrer" <[EMAIL PROTECTED]>
Crossposted-To: sci.crypt.random-numbers
Subject: Re: LFSR Security
Date: Fri, 20 Apr 2001 18:12:52 -0700
David Wagner <[EMAIL PROTECTED]> wrote in message
news:9bj17i$1nv$[EMAIL PROTECTED]...
> Scott Fluhrer wrote:
> >One obvious way to extend this is to make the wild claim that, if the
> >keystream bits you do have, there exists a a_0 < a_1 < ... < a_{n+1} and
n-1
> >distinct r_0, ..., r_{n-2}, you know the keystream output for b_{a_i +
r_j}
> >for all i, j, then you can derive the taps for a virtual LFSR (which
> >hopefully isn't too hard to translate back into the normal form).
>
> Ooh, nice. Sounds promising.
>
> Yes, it seems plausible that if you can find the taps for a virtual
> LFSR, one can hope to recover the taps of the original LFSR. Your
> virtual LFSR is basically a recurrence relation
> b_{m+r_0} + b_{m+r_1} + ... + b_{m+r_n} = 0 for all m.
> The associated polynomial is q(x) = x^r_0 + x^r_1 + .. + x^r_n.
> Now the LFSR's polynomial is a divisor of q(x), so if you factor
> q(x), you can get some candidates for the LFSR taps. Alternatively,
> if you get a few such q(x)'s, you can take their gcd.
>
> It seems to me that one of the major remaining questions is this:
> Suppose we know the keystream at some set of positions S (i.e., we
> known b_s for s in S). How do we find a_i's and r_j's so that
> a_i + r_j is in S for all i,j? Moreover, how much known text is
> needed to ensure that such a_i,r_j's exist?
For a simple answer to your second question: you are never guarranteed. In
particular, there are infinite sets S s.t. for any foursome a_1, a_2, r_1,
r_2 (a_1!=a_2, r_1!=r_2), at least one of the a_i + r_j will always be
outside of S. One such S is the set of all powers of 2.
>
> To rephrase the first question: We have a set S. We want to find a
> pair of sets, A and R, of cardinality >= n such that A+R is a subset
> of S. Here A+R denotes {a+r : a in A, r in R}, and A represents the
> set of a_i's, R the set of r_j's. How large does S need to be?
> Can we find A,R efficiently?
I've flailed away at it, and couldn't find anything workable. I did find
that the obvious greedy algorithm doesn't pan out -- if it doesn't find a
solution quickly, it goes into exponential time behavior. The problem feels
like it might be NP-complete, although I have been unable to construct a
reduction.
--
poncho
------------------------------
From: "Scott Fluhrer" <[EMAIL PROTECTED]>
Subject: Re: First cipher
Date: Fri, 20 Apr 2001 18:16:56 -0700
<[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED]...
> David Wagner wrote:
> >
> > >Supposedly, if the S-box is reversible and the number of bits per table
> > >entry is large, then the probability of a random S-box having one or
> > >more bits that are linear functions of the address bits is low.
> >
> > (... if the S-box is large enough, and is selected at random.)
> >
> > >Ah, but at one time each one of them was a neophyte just like me.
> >
> > Yes, but designing new ciphers is unlikely to be the best way to
> > learn how to design new ciphers. (Sounds counter-intuitive, but
> > it seems to be true.)
>
> I'd be glad to start paying my dues on the cryptanalysis end of things.
> The problem seems to be finding a consolidated, unified guide in the
> literature.
Why don't you get started on your own cipher. 16 rounds may be too tough
for a neophyte, so you may want to reduce it to 4-6. You'll also need to
fill in the details (eg. exactly what permutation is 'permute'?) I've
already given you hints about one possible line of attack...
--
poncho
------------------------------
From: "Scott Fluhrer" <[EMAIL PROTECTED]>
Subject: Re: Basic AES question
Date: Fri, 20 Apr 2001 18:22:14 -0700
Joseph Ashwood <[EMAIL PROTECTED]> wrote in message
news:e33aV1dyAHA.344@cpmsnbbsa07...
> There are certain hedge bets against that. For example there is a maximum
> number of rounds of Rijndael/AES before it maps back to itself, and in
order
> to make use of larger keys you need to increase the number of rounds. Also
> there are typically attacks that have a fixed complexity regardless of key
> size, the one that comes to mind if RC6 had one at IIRC 2^772 work, making
> any use of keys larger than 772-bits worthless.
ObNit: I think you're thinking of RC4
--
poncho
------------------------------
From: [EMAIL PROTECTED] (Nemo psj)
Date: 21 Apr 2001 01:51:49 GMT
Subject: Re: Will this defeat keyloggers ?
You could just make a keypad on the screen and have them clikc in the
passphrase.... In this way the only keys registerd are the mouse clicks.
-Jay
------------------------------
From: newbie <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Fri, 20 Apr 2001 21:49:52 -0300
You are talking like a dictator.
English is not my native language.
Is that clear?????????
Do you speak french?
Do you speak spanish?
Do you speak arabic?
Do you speak other african dialects you do not even know if they exist?
Tom St Denis wrote:
>
> "newbie" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > How could you know that the keystream used to Xor plaintext is truly
> > random?????????
> > Truly random is ideal situation. In practice, we measure randomness
> > degree. How you measure it????????????
> > How could you distinguish between truly random or not??????
> > You have to apply statistical tests.
> > So I suppose that the keystream used is truly random. That means that
> > this keystream was filtred by statistical tests. So I have still the
> > ability to know if my input 10100010010110 Xored with my ciphertext
> > 100100100100 give me truly random sequence or not.
> > The keysteam used is truly random BUT MY OUTPUT IS NOT NECESSARLY TRULY
> > RANDOM.
>
> Write properly or don't write at all. I make grammar mistakes and such but
> I form my questions a tad better.
>
> if X is a truly random bit then 1 xor X is truly random and so is 0 xor X.
> Your question is moot.
>
> Tom
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Sat, 21 Apr 2001 02:00:58 GMT
"newbie" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> You are talking like a dictator.
> English is not my native language.
> Is that clear?????????
> Do you speak french?
> Do you speak spanish?
> Do you speak arabic?
> Do you speak other african dialects you do not even know if they exist?
That's not the point. If I went to france in a non-tourist part of country
would I be greeted by everyone in english? Nope, nor should I expect to be.
This group is primarily english (well at least their posts). It wouldn't
hurt to speak (or write) a bit more concisely. You're posts are vague and
ambiguous at best.
Tom
------------------------------
From: newbie <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Fri, 20 Apr 2001 21:55:31 -0300
10100010010 is random string
the inverse 01011101101 is random too.
but if you Xor the two random string you will find
111111111111111111111111111111
random + random does not give you random result.
random + non random does not give you 100 % random result.
You have to meet some conditions before claiming that those equality are
true.
Tom St Denis wrote:
>
> "newbie" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > How could you know that the keystream used to Xor plaintext is truly
> > random?????????
> > Truly random is ideal situation. In practice, we measure randomness
> > degree. How you measure it????????????
> > How could you distinguish between truly random or not??????
> > You have to apply statistical tests.
> > So I suppose that the keystream used is truly random. That means that
> > this keystream was filtred by statistical tests. So I have still the
> > ability to know if my input 10100010010110 Xored with my ciphertext
> > 100100100100 give me truly random sequence or not.
> > The keysteam used is truly random BUT MY OUTPUT IS NOT NECESSARLY TRULY
> > RANDOM.
>
> Write properly or don't write at all. I make grammar mistakes and such but
> I form my questions a tad better.
>
> if X is a truly random bit then 1 xor X is truly random and so is 0 xor X.
> Your question is moot.
>
> Tom
------------------------------
From: newbie <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Fri, 20 Apr 2001 22:02:35 -0300
I'm trying to speak correctly. You are the only one to tell that.
Tom St Denis wrote:
>
> "newbie" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > You are talking like a dictator.
> > English is not my native language.
> > Is that clear?????????
> > Do you speak french?
> > Do you speak spanish?
> > Do you speak arabic?
> > Do you speak other african dialects you do not even know if they exist?
>
> That's not the point. If I went to france in a non-tourist part of country
> would I be greeted by everyone in english? Nope, nor should I expect to be.
> This group is primarily english (well at least their posts). It wouldn't
> hurt to speak (or write) a bit more concisely. You're posts are vague and
> ambiguous at best.
>
> Tom
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Sat, 21 Apr 2001 02:09:25 GMT
"newbie" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> 10100010010 is random string
> the inverse 01011101101 is random too.
> but if you Xor the two random string you will find
> 111111111111111111111111111111
> random + random does not give you random result.
> random + non random does not give you 100 % random result.
> You have to meet some conditions before claiming that those equality are
> true.
You still don't get it. If the chance of "11111111" of occuring is 1/256
then it's random!!
Christ 11111111 is equal to 255, so you are saying that no truly random
number generator can't output 255? Then how can it be random?
You're plain mad.
Tom
------------------------------
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