Cryptography-Digest Digest #539, Volume #13 Wed, 24 Jan 01 10:13:00 EST
Contents:
Re: Some Enigma Questions (Richard Heathfield)
Re: Why Microsoft's Product Activation Stinks (Anthony Stephen Szopa)
Re: Why Microsoft's Product Activation Stinks (Anthony Stephen Szopa)
Re: Why Microsoft's Product Activation Stinks (Anthony Stephen Szopa)
Re: Snake Oil (Anthony Stephen Szopa)
Re: ___MIPS rating of a Pentium II-400 MHz (Darryl Wagoner - WA1GON)
Re: O.T. Corpspeak was (Why Microsoft's Product...) (Anthony Stephen Szopa)
Re: Dynamic Transposition Revisited (long) (Mok-Kong Shen)
Re: rubik's cube (digiboy | marcus)
How many bits of security can a password give? (Erik Runeson)
Re: Why Microsoft's Product Activation Stinks (Richard Heathfield)
Re: Producing "bit-balanced" strings efficiently for Dynamic Transposition (John
Savard)
Re: Dynamic Transposition Revisited (long) (Benjamin Goldberg)
Patents on modes of operation (Ulrich Kuehn)
----------------------------------------------------------------------------
Date: Wed, 24 Jan 2001 12:37:51 +0000
From: Richard Heathfield <[EMAIL PROTECTED]>
Subject: Re: Some Enigma Questions
"Douglas A. Gwyn" wrote:
>
> "David C. Barber" wrote:
> > Of course, the Germans kept thinking the machine was unbreakable
> > because they couldn't break it themselves.
>
> More accurately, they didn't see any way of breaking it
> short of exhaustive key search (including steckering),
> and thus were lulled by the vast number of combinations
> into a (false) sense of security. Much like people who
> think any old 1024-bit-keyed block cipher is just fine.
You mean it isn't?
<g,d&r>
--
Richard Heathfield
"Usenet is a strange place." - Dennis M Ritchie, 29 July 1999.
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R Answers: http://users.powernet.co.uk/eton/kandr2/index.html
------------------------------
From: Anthony Stephen Szopa <[EMAIL PROTECTED]>
Crossposted-To: or.politics,talk.politics.crypto,misc.survivalism
Subject: Re: Why Microsoft's Product Activation Stinks
Date: Wed, 24 Jan 2001 04:07:55 -0800
Gordon Walker wrote:
>
> On Mon, 22 Jan 2001 23:30:18 -0800, Anthony Stephen Szopa
> <[EMAIL PROTECTED]> wrote:
>
> >Did you develope an anti-piracy computer software module that will
> >prevent perhaps half at a minimum of the illegal copying of
> >computer software in the world? Do you know how important a
> >contribution this is?
>
> Personally I wouldn't boast about it even if I had invented the thing.
> In Windows it will prove to be an annoyance that will in no way slow
> down real piracy and will rather only damage sales. In the mass market
> the scheme is infeasible.
> --
> Gordon
With sufficient motivation many things once thought undoable get
done.
------------------------------
From: Anthony Stephen Szopa <[EMAIL PROTECTED]>
Crossposted-To: or.politics,talk.politics.crypto,misc.survivalism
Subject: Re: Why Microsoft's Product Activation Stinks
Date: Wed, 24 Jan 2001 04:17:08 -0800
Joseph Ashwood wrote:
>
> I should have jumped on this sooner, and noticed that Szopa was posting to
> several groups for this. For those that are uninformed about the general
> concensus about Szopa, please have a look at the newsgroup history
> surrounding Szopa in sci.crypt (www.deja.com will be helpful). He is
> generally considered very offensive.
>
> However in this case I think he has brought up an important. I don't think
> he will benefit from any suit he brings against Microsoft, if for no other
> reason than they can afford to hire a legal team that physically crowds him
> out of the court room, while he is I assume only monetarily capable of
> affording one. Szopa I hope you were smart enough for your lawyer to take
> this on speculation, and I hope your lawyer was smart enough to charge you
> instead. If he wasn't I'd drop him, he's not smart enough to take on the M$
> horde. Best of luck (I may dislike Szopa but if he has a legitimate reason
> to believe M$ has performed their typical embrace and devour tactic I
> support his cause).
> Joe
>
> "Anthony Stephen Szopa" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > Richard Heathfield wrote:
> > >
> > > Anthony Stephen Szopa wrote:
> > > >
> > > <snip over 200 lines>
> > > >
> > > > So that's all I have to say for a while.
> > >
> > > Is that a promise?
> >
> >
> > Here is a guy who spits on the souls of anyone for no damned reason.
> >
> > I told you that I am the inventor that will save people tens or
> > hundreds of billions of dollars in lost revenue and you verbally
> > shit on me with your sarcasm.
> >
> > Did you develope an anti-piracy computer software module that will
> > prevent perhaps half at a minimum of the illegal copying of
> > computer software in the world? Do you know how important a
> > contribution this is?
> >
> > I can prove that I did this. And if I eventually do prove it
> > publicly everyone will know you are a fool. But most importantly
> > you will know. I think you probably already know you are a fool.
> >
> > I am certainly one of a very very few and perhaps the only person in
> > the world who can prove that they did it before MS. I am not going
> > to divulge my thought processes here or my plans or my actions
> > regarding the implications of this situation at this time, as I have
> > said. I am actively pursuing my interests.
> >
> > I think I read that there is about $50 billion dollars worth of
> > computer software piracy going on every year.
> >
> > You must be a real high achiever to top this. Tell your friends
> > what a proud soul you are and give them the example you posted here
> > and explain to them why you are the one to be so sarcastic. What
> > are your qualifications?
> >
> > I would tell them that you are a high risk gambler and that they
> > should stay as far away from you as possible. You just can't
> > believe that I did what I say I did, can you? You think you can
> > make the jump and take the leap to ridicule me. You have no proof
> > that I am lying. Yet you risk your reputation. As I said, you have
> > poor judgment although you have calculated that you are on solid
> > ground. Quicksand, yes. You are in quicksand and there will be no
> > one to come to your aid. Just wait and see.
> >
> > If and when the proof comes out I hope someone brings it to you
> > attention.
> >
> > I was waiting for a worm to show their slime. You finally showed up.
> >
> > What is a fool? A fool is a person who plays an Eric Clapton song
> > on their own guitar. He plays the song perhaps even as good as Eric
> > Clapton. And then he thinks he is as great an artist as Eric
> > Clapton.
> >
> > You are an even greater fool than this because you would play the
> > air guitar while listening to Eric Clapton and really believe you
> > are as great a musician and artist as Eric Clapton.
> >
> > Can you feel your heart literally shrinking? You will.
> >
> > Thanks a lot.
> >
> > AS
> >
> >
> > Gee, you didn't get any more significant information from me about
> > my claim?
> >
> > Too bad.
Another disbeliever.
Like I am still waiting for anyone to come up with a reasonable
suggestion on how to break my encryption software.
One person tried to make a show of it but in effect was demanding
the key once removed and then claiming that with it he could break
the encryption. I think not. You cannot have the key or the key
once removed.
What now?
A talking cat?
Well, yeah.
I saw a guy on TV who used to go into bars and bet people at the bar
$50 that his cat could talk. He had to stop because he was getting
thrown in jail for it: it is illegal gambling. Sore losers were
calling the cops.
Seems that his cat can talk. It can say about five words, I think it
was. Damnedest thing I ever saw. He was on Johnny Carson, I think
it was. And the cat said a couple of the five words it knew into the
microphone on Carson's show!
Wanna bet fifty I don't got a talking cat?
------------------------------
From: Anthony Stephen Szopa <[EMAIL PROTECTED]>
Crossposted-To: or.politics,talk.politics.crypto,misc.survivalism
Subject: Re: Why Microsoft's Product Activation Stinks
Date: Wed, 24 Jan 2001 04:18:11 -0800
Noah Simoneaux wrote:
>
> On Tue, 23 Jan 2001 11:46:07 -0800, "Joseph Ashwood" <[EMAIL PROTECTED]> wrote:
>
> >I should have jumped on this sooner, and noticed that Szopa was posting to
> >several groups for this. For those that are uninformed about the general
> >concensus about Szopa, please have a look at the newsgroup history
> >surrounding Szopa in sci.crypt (www.deja.com will be helpful). He is
> >generally considered very offensive.
>
> I was wondering about those initials. ASS? ;)
>
> (snip)
>
> Noah Simoneaux
> Each of us is a mixture of good qualities and some(perhaps) not-so-good qualities.
>In considering our fellow people, we should remember their good qualities and realize
>that their faults only prove that they are, after all, only human. We should refrain
>from making harsh judgments of people just because they happen to be dirty rotten
>sons-of-bitches.
>
> -----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
> http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
> -----== Over 80,000 Newsgroups - 16 Different Servers! =-----
You'll be calling yourself an ass soon enough.
------------------------------
From: Anthony Stephen Szopa <[EMAIL PROTECTED]>
Crossposted-To: or.politics,talk.politics.crypto,misc.survivalism
Subject: Re: Snake Oil
Date: Wed, 24 Jan 2001 04:21:49 -0800
William Hugh Murray wrote:
>
> Anthony Stephen Szopa wrote:
>
> > Richard Heathfield wrote:
> > >
> > > Anthony Stephen Szopa wrote:
> > > >
> > > <snip over 200 lines>
> > > >
> > > > So that's all I have to say for a while.
> > >
> > > Is that a promise?
> >
> > Here is a guy who spits on the souls of anyone for no damned reason.
> >
> > I told you that I am the inventor that will save people tens or
> > hundreds of billions of dollars in lost revenue and you verbally
> > shit on me with your sarcasm.
>
> > <snip>
>
> > Gee, you didn't get any more significant information from me about
> > my claim?
> >
> > Too bad.
>
> My Daddy told me, "Son, if it looks like snake oil, tastes like snake
> oil, and a smells like snake oil, it is usually snake oil." My Daddy was
> a wise man and he loved me very much. He rarely misled me.
>
> We see a lot of claims here that look like snake oil. Sci.crypt seems to
> attract more than its fair share of snake oil. We are very sensitive to
> snake oil and have a very low tolerance for it. This is not a place for
> unsupported assertions. It is not a place for the discussion of trade
> secrets or pending patents. These might be snake oil; it is not
> possible to tell. It is not personal it, is just sci.crypt.
>
> We have noticed that snake oil salesmen have very thin skins; they are
> easily provoked and become very defensive. One can often detect a snake
> oil salesman by taking a little poke at him and watching to see how he
> walks and talks. If he walks like a snake oil salesman and talks like a
> snake oil salesman, he may be a snake oil salesman; one cannot tell for
> sure. Sci.crypt attracts a lot of snake oil salesmen and we tend to have
> a very low tolerance for them. We have a low tolerance for people who
> are overly defensive. It is not personal, it is just sci.crypt.
>
> Being a great inventor, humanist, philosopher, or philanthropist is not
> much of a defense here. We might not crucify Jesus Christ here but we
> would certainly contribute the hammer and the nails. It is not personal,
> it is just sci.crypt.
>
> Please do not take it personally or go away mad; just go away. There
> are probably lots of forums that will appreciate you for the great human
> being that you are. We are not one of them. It is not personal, it is
> just sci.crypt.
It's 2001.
You cannot lie anymore these days and not get caught.
Take my encryption software. Give it a go. Prove to us you can
break it. Give us your most tenuous reasonable explanation on how you
would go about it.
Or do you just talk about snake oil having never known what it really
is?
------------------------------
From: [EMAIL PROTECTED] (Darryl Wagoner - WA1GON)
Subject: Re: ___MIPS rating of a Pentium II-400 MHz
Date: Wed, 24 Jan 2001 12:31:17 -0000
[EMAIL PROTECTED] (kctang) wrote in <[EMAIL PROTECTED]>:
>Dear Forum,
>
>(Excuse me! I posted this news to intel-xxxx newsgroups before but
>received no reply yet.)
>
>
>What is the MIPS rating of a Pentium II-400 MHz?
I don't know about real MIPS but PII/400 is 600 bogomips
from Linux. I do have to agree with the rest that it
is fairly meaningless, unless you know exactly what it
means and I don't. If you still are interested what
the other classes of Pentiums are I have a PIII/866
and a PIII/1G at work that I can check. Send me
email.
-darryl
------------------------------
From: Anthony Stephen Szopa <[EMAIL PROTECTED]>
Crossposted-To: talk.politics.crypto,misc.survivalism
Subject: Re: O.T. Corpspeak was (Why Microsoft's Product...)
Date: Wed, 24 Jan 2001 04:29:55 -0800
Paul Pires wrote:
>
> > Can anyone tell me if I have a case with MS? Has MS attempted to
> > patent their anti-piracy feature they hope the industry will adopt?
> > I will have to check to see if I even applied for a patent on this.
> > I may have but I can tell you that if I did that the provisional
> > patent has certainly expired. What about a trade secret case?
> >
> > Did I blow it or what? MAYBE BIG TIME???!!!
>
> Maybe. Maybe you are being paranoid and this was an independent
> developement. The LEAST likely way to get a big company to
> evaluate a concept is to submit it to their Outside Concepts Evaluation
> Department. This is less likely to work than triple encrypting it with
> 128 bit keys, loosing the keys and not mailing them the ciphertext.
>
> You have to talk corpspeak. Do you think "Accounts Payable" is there
> to make sure every account gets paid on time? More like "Accounts
> Avoidable".
>
> Trade Secret is a contract not a grant. Read your contract and see if
> A, they violated it.
> B, you can prove it.
> C, it is damaging.
>
> You do have a contract, don't you?
>
> Just because they were in possesion of Your stuff, doesn't make it
> "Prior Art" and a bar to thier filing. The requirement is for it to
> be "Publically Known" in the legal sense, not a Biblical sense.
>
> Go ahead if you have the free time. File suit. Maybe they will
> offer a small settlement just to avoid the cost of plane tickets for their
> legal staff (Got to be a large figure). If it nets you anything over
> expenses, TAKE IT.
>
> By The way, I read your response to Richard Heathfield.
> If this is the basis for your Ire, well, you play a mean air guitar
> too. If it starts to run low, just plug it into your head.
>
> Paul
>
> -----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
> http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
> -----== Over 80,000 Newsgroups - 16 Different Servers! =-----
I cannot post my reply. It would be too informative.
MS is in a difficult situation.
------------------------------
From: Mok-Kong Shen <[EMAIL PROTECTED]>
Subject: Re: Dynamic Transposition Revisited (long)
Date: Wed, 24 Jan 2001 13:53:13 +0100
John Savard wrote:
>
> [EMAIL PROTECTED] (Terry Ritter) wrote, in part:
[snip]
> But you appear to be claiming that the availability of every possible
> bit transposition provides some important fundamental property, and
> that it challenges the OTP. These are indeed the kinds of claims that,
> if true, might well induce people to accept a 2.5% bandwidth penalty.
> But I haven't seen these claims justified in a way that will win
> general acknowledgement. Worse than that, I still believe these claims
> to be mistaken, and I feel that others will do so as well - to the
> extent they even deign to investigate.
Elsewhere I said that there cannot exist any magic that
turns something predictable (the best PRNG is not 'absolutely'
unpredicatble) to something (absolutely) unpredictable.
This suffices to convince one that, while DT might be
extremely good so as to be practically very very secure, it,
like all other 'real' algorithms, can't attain the goal of
'perfect' security, which is neither possible nor truly
necessary (to attempt) to attain (with all prices) in
practice.
M. K. Shen
=================================
http://home.t-online.de/home/mok-kong.shen
------------------------------
From: digiboy | marcus <[EMAIL PROTECTED]>
Crossposted-To: comp.security.pgp.discuss
Subject: Re: rubik's cube
Date: Wed, 24 Jan 2001 13:58:28 GMT
In article <[EMAIL PROTECTED]>,
"Douglas A. Gwyn" <[EMAIL PROTECTED]> wrote:
> Rubik's cube involves very simple finite groups,
> and is therefore a horrible basis for encryption.
Even for a pen-and-paper(-and-rubik's cube) cipher? Surely there could
be something of substance derived from it?
--
[ marcus ] [ http://www.cybergoth.cjb.net ]
[ ---- http://www.ninjakitten.net/digiboy ]
Sent via Deja.com
http://www.deja.com/
------------------------------
From: Erik Runeson <[EMAIL PROTECTED]>
Subject: How many bits of security can a password give?
Date: Wed, 24 Jan 2001 14:01:20 GMT
I'm doing some analysis on how many bits of security a password can
provide.
For instance, if we take a password with 8 random characters (all lower
case to simplify a bit), it is easy to assume that it would mean:
8*8=64 bits of security (since each character is 8 bits).
However, since there are only 26 lower case letters, the actual figure
is:
log2( 26^8 ) = 37.6 bits
Of course, the whole issue gets a lot more complicated when you add
upper case letters, numbers and other characters, as well as dealing
with the fact that users rarely choose random passwords.
Does anyone know any articles or other studies in this area?
- Erik Runeson
---
Disclaimer: This post represent my personal views,
not those of my employer.
Sent via Deja.com
http://www.deja.com/
------------------------------
Date: Wed, 24 Jan 2001 15:28:33 +0000
From: Richard Heathfield <[EMAIL PROTECTED]>
Crossposted-To: or.politics,talk.politics.crypto,misc.survivalism
Subject: Re: Why Microsoft's Product Activation Stinks
[Sorry to reply to Joe's post when I'm really addressing the issues
raised by Mr Szopa. Mr Szopa's article hasn't hit my newsfeed yet and
may not do so for some time...]
> "Anthony Stephen Szopa" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > Richard Heathfield wrote:
> > >
> > > Anthony Stephen Szopa wrote:
> > > >
> > > <snip over 200 lines>
> > > >
> > > > So that's all I have to say for a while.
> > >
> > > Is that a promise?
> >
> >
> > Here is a guy who spits on the souls of anyone for no damned reason.
I guess it wasn't a promise after all. (sigh)
> >
> > I told you that I am the inventor that will save people tens or
> > hundreds of billions of dollars in lost revenue and you verbally
> > shit on me with your sarcasm.
You do a good line in invective. Perhaps you should switch from crypto
to politics.
> > Did you develope an anti-piracy computer software module that will
> > prevent perhaps half at a minimum of the illegal copying of
> > computer software in the world?
Certainly not. I wouldn't dream of writing such a pointless program.
> > Do you know how important a contribution this is?
It's completely insignificant to those who have already realised that MS
has, for years, been using the very best copy protection of all - i.e.
products that don't work, products that corrupt files, products that
hang the machine... Why would anyone with the slightest semblance of
common sense *want* to copy programs like that?
> > I can prove that I did this. And if I eventually do prove it
> > publicly everyone will know you are a fool. But most importantly
> > you will know. I think you probably already know you are a fool.
If you really were conned by MS, I sympathise (like Joe), but am stunned
by your naivete.
1) Copy protection doesn't work. sci.crypt already knows this. Why don't
you?
2) Microsoft is well-known for exploiting anything it can exploit.
> > I am certainly one of a very very few and perhaps the only person in
> > the world who can prove that they did it before MS.
You're the guy with the proprietary no-source-code-provided technique
for XORing two files together, yes? The one with the front end that
looks like something the cat dragged in? The one you said was so
innovative?
> > I am not going
> > to divulge my thought processes here or my plans or my actions
> > regarding the implications of this situation at this time, as I have
> > said.
Excellent.
> > I am actively pursuing my interests.
> >
> > I think I read that there is about $50 billion dollars worth of
> > computer software piracy going on every year.
Well, people will play those games, I suppose.
If you don't want people to steal your software, give it away. It's that
simple.
> > You must be a real high achiever to top this. Tell your friends
> > what a proud soul you are and give them the example you posted here
> > and explain to them why you are the one to be so sarcastic.
Righty-ho, I'll do that.
> > What are your qualifications?
I can write a program to XOR two files together. Does that count? (It
seems to be a significant achievement from your point of view, if I
correctly recall your proud boasts of about three months back.)
> > I would tell them that you are a high risk gambler and that they
> > should stay as far away from you as possible.
Interesting. I have made exactly two serious bets in my entire life. In
each case, I calculated the probability of my winning to be 1.0. In each
case, I won the bet. If the probability of victory is < 1.0, I don't
bet.
> > You just can't believe that I did what I say I did, can you?
Yes, I can believe that you could design a copy protection protocol
(albeit an inherently flawed protocol, as all such schemes are). What I
was having difficulty with was your stupidity in showing it to
Microsoft.
> > You think you can
> > make the jump and take the leap to ridicule me.
You're doing fine all by yourself.
> > You have no proof that I am lying.
"The wicked flee when no man pursueth." (Prov 28:1)
I have not accused you of lying. I am quite prepared to believe that you
have invented a copy protection protocol. I can even take a guess as to
how it might work. The potential software pirate has to shuffle some
cards, yes?
The fact that you deny lying without being accused of it, however, is in
itself deeply suspicious.
> > Yet you risk your reputation.
That's all right. My reputation on sci.crypt is "cute and fluffy, and
has at least quarter of a brain, if not slightly more, but can't
cryptanalyse anything harder than Vigenere", and I'm certainly prepared
to risk that. Strangely, your reputation on sci.crypt seems to be even
worse than mine. Odd, that.
> > As I said, you have
> > poor judgment although you have calculated that you are on solid
> > ground. Quicksand, yes. You are in quicksand and there will be no
> > one to come to your aid. Just wait and see.
/me checks his immediate environment...
Aarrgghh! You're right! Quicksand! I'm sinking! Quick, somebody... SAVE
ME! SAVE ME! Don't leave me to a horrible death!!!
Oh, hang on, it's okay, it's just carpet. Panic over.
> > If and when the proof comes out I hope someone brings it to you
> > attention.
Well, you could always post the source to alt.sources.crypto. I'll see
it there, I expect. Oh, can you make sure it works in Linux please?
Thanks.
> > I was waiting for a worm to show their slime. You finally showed up.
It is not surprising that a purveyor of snake oil should see the world
in terms of long thin creatures.
> >
> > What is a fool? A fool is a person who plays an Eric Clapton song
> > on their own guitar. He plays the song perhaps even as good as Eric
> > Clapton. And then he thinks he is as great an artist as Eric
> > Clapton.
By that definition, Eric Clapton is a fool - which I don't believe.
Therefore, the definition is wrong.
> > You are an even greater fool than this because you would play the
> > air guitar while listening to Eric Clapton and really believe you
> > are as great a musician and artist as Eric Clapton.
Actually, I play a pretty mean "Layla", but I wouldn't claim to be in
the same league as EC.
> >
> > Can you feel your heart literally shrinking? You will.
Do you literally mean "literally" literally?
> > Gee, you didn't get any more significant information from me about
> > my claim?
> >
> > Too bad.
Ah! You caught me out! Yes! I was trying to do industrial espionage over
Usenet, like all the best spies, but the ever-clever Mr Szopa was too
smart for me, and foiled my cunning plan. I am exactly as chagrined,
chastised, and chastened as I ought to be.
I sometimes wonder what planet you're on. On my home account (not this
account, you understand), I killfiled you well over a year ago. That may
have been a mistake, as you are proving to be a plentiful, albeit
unwitting, source of humour. Mind you, I suppose sci.crypt can live
without regular flame battles between us, so perhaps it's just as well.
--
Richard Heathfield
"Usenet is a strange place." - Dennis M Ritchie, 29 July 1999.
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R Answers: http://users.powernet.co.uk/eton/kandr2/index.html
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Producing "bit-balanced" strings efficiently for Dynamic Transposition
Date: Wed, 24 Jan 2001 14:36:53 GMT
Well, I finally came up with an algorithm that is reasonably workable.
To convert 37-bit arbitrary strings into 40-bit bit-balanced strings,
I need an _enumeration_ of 40-bit balanced strings. Instead of
directly splitting up a 40-bit bit-balanced string into five 8-bit
strings, I can keep the number of cases manageable if I split it up
into two 20-bit strings.
Thus, I have the cases
(10)(10)
(11)(9) and (9)(11)
(12)(8) and (8)(12)
...
(20)(0) and (0)(20)
To actually produce the bits of 40-bit string number such-and-such, I
simply _continue the process_.
Thus, a bit-balanced 20-bit string becomes two 10-bit strings:
(5)(5)
(6)(4) and (4)(6)
...
(10)(0) and (0)(10)
and a 20-bit string with 11 zeroes and 9 ones also becomes two 10-bit
strings, this time with the cases
(5)(4) and (4)(5)
(6)(3) and (3)(6)
...
(9)(0) and (0)(9)
and I can even split the 10 bit strings into two 5-bit strings.
Doing a cascading conversion in this way means that I have a limited
number of cases at each step, so the tables I work with have
reasonable size.
John Savard
http://home.ecn.ab.ca/~jsavard/crypto.htm
------------------------------
From: Benjamin Goldberg <[EMAIL PROTECTED]>
Subject: Re: Dynamic Transposition Revisited (long)
Date: Wed, 24 Jan 2001 15:00:42 GMT
John Savard wrote:
[snip]
> I
> don't see why I shouldn't point out that Dynamic Transposition is also
> not a true general substitution of bit-balanced blocks.
>
> Ah, but it's a transposition, and it is a "true general
> transposition", you seem to have said.
Might I ask, what do you mean by "true general substitution" and "true
general transposition?"
With sufficiently large state in the PRNG, one might expect that DT is
capable of producing any of the N! possible permutations as it's first
output. Is this what is meant by "true general transposition?"
Now suppose that we use the PRNG to generate round keys for some well
known block cipher [2 round DES, as you suggested] with a similarly
large state. Perhaps one might hope that the first output of this can
be any of the (2^64)! different permutations, as with DT, but it is not.
I suppose that this could probably be said to NOT be a "true general
substitution," whatever that might be.
What would be a "true general substitution," then?
Another way of looking at things:
DT creates a permutation of N items to N items.
DES creates a permutation of 2^64 items to 2^64 items.
It is easy to pick N and the PRNG so that DT produces any of the N!
permutations for it's first output. It is [nearly?] impossible to pick
a PRNG [and some number of rounds] to use with DES to produce any of the
2^64! permutations as it's first output.
--
Most scientific innovations do not begin with "Eureka!" They begin with
"That's odd. I wonder why that happened?"
------------------------------
From: Ulrich Kuehn <[EMAIL PROTECTED]>
Subject: Patents on modes of operation
Date: Wed, 24 Jan 2001 16:03:55 +0100
Reply-To: [EMAIL PROTECTED]
Hi everybody,
I would like to know if there are any patents that cover the standard
modes of operation as specified in FIPS 81 for DES.
While the FIPS was published in 1980, any patents covering its contents
should be expired by now. But then, I am not too familiar with patent
law and for how long a patent is granted exactly. (HAC speaks about 20
years from filing or 17 from granting date, and that before 1995 a
different rule applies.) Are there some specific pointers?
A web search turned up only that FIPS 81 says that there may be patents,
US or foreign, that apply. But I could not find a definitive negative
answer.
Ciao,
Ulrich
------------------------------
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