Cryptography-Digest Digest #176, Volume #14 Wed, 18 Apr 01 16:13:00 EDT
Contents:
Re: Reusing A One Time Pad (SCOTT19U.ZIP_GUY)
Re: Reusing A One Time Pad ("Tom St Denis")
Re: Reusing A One Time Pad ("Tom St Denis")
WHY I HATE BOSCHLOO (Fight Boschloo)
Re: XOR TextBox Freeware: Very Lousy. (David Schwartz)
Re: "UNCOBER" = Universal Code Breaker (Jim Gillogly)
Re: "UNCOBER" = Universal Code Breaker ("Tom St Denis")
Re: A practical idea to reinforce passwords (Bill Unruh)
Re: XOR TextBox Freeware: Very Lousy. ("Joseph Ashwood")
Re: "UNCOBER" = Universal Code Breaker (Jim Gillogly)
Re: New to cryptography but in need of encryption :o) ("M.S. Bob")
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (SCOTT19U.ZIP_GUY)
Subject: Re: Reusing A One Time Pad
Date: 18 Apr 2001 17:55:56 GMT
[EMAIL PROTECTED] (Tom St Denis) wrote in
<%akD6.43502$[EMAIL PROTECTED]>:
>
>"SCOTT19U.ZIP_GUY" <[EMAIL PROTECTED]> wrote in message
>news:[EMAIL PROTECTED]...
>> [EMAIL PROTECTED] (Tom St Denis) wrote in
>> <fLiD6.43031$[EMAIL PROTECTED]>:
>>
>> >"Modestly large OTP" is a meaningless description. An OTP must by
>> >definition be the same size as the message. And if it's a true OTP
>> >you need not encrypt it any "further" to get a more secure system,
>> >it's already provably secure.
>> >
>>
>> Actually an OTP does does not have to be the same size as the
>> message sent. Suppose one defines the set of all messages that
>> one wants to encrypt to be 1000 bytes max. By 1000 bytes I mean
>> that is the length after compression and the bijective padding
>> transformtion to get the data to exactly 1000 bytes. At this point
>> you use 1000 fresh bytes of your OTP to encode the message. This
>> would be far more secure than using a OTP on the message and
>> leaving the length information there for the taking.
>
>Um no actually you're wrong. Even given the length of the message you
>cannot break an OTP. Knowing the length does not give you any useful
>information about the actual message other than's it's length.
>
No Tom as with huffman compression not ever being optimal you
are wrong. The concept in volved was wether or not it would be
more secure. Pefect security involves no information as to the
possible solution of the encrypted message. It does not mean
that the attacker completely decodes a message. The larger the
set of possible messages the more uncertain of what the actual
encrypted messages was and there fore the more secure.
Your example of yes or no was a good one. If I ask someone
a yes or no type of question and the encrypted OTP answer
comes out as "QW" I think the responce may have been NO.
While if "ZXV" was the encrypted response I think the
anwser was YES. If one sent 1000 characters encrypted with
a OTP you have no idea if he answersed "YES","NO,"MAYBE",
SOMETIMES",or he may have asked for further clarification.
I think if you stop to think about it or you can even ask
Wagner since the source of the response seems to affect you
more that the truth of it. You may get to finally see the light.
David A. Scott
--
SCOTT19U.ZIP NOW AVAILABLE WORLD WIDE "OLD VERSIOM"
http://www.jim.com/jamesd/Kong/scott19u.zip
My website http://members.nbci.com/ecil/index.htm
My crypto code http://radiusnet.net/crypto/archive/scott/
MY Compression Page http://members.nbci.com/ecil/compress.htm
**NOTE FOR EMAIL drop the roman "five" ***
Disclaimer:I am in no way responsible for any of the statements
made in the above text. For all I know I might be drugged or
something..
No I'm not paranoid. You all think I'm paranoid, don't you!
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: Reusing A One Time Pad
Date: Wed, 18 Apr 2001 18:19:20 GMT
"SCOTT19U.ZIP_GUY" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> No Tom as with huffman compression not ever being optimal you
> are wrong. The concept in volved was wether or not it would be
> more secure. Pefect security involves no information as to the
> possible solution of the encrypted message. It does not mean
> that the attacker completely decodes a message. The larger the
> set of possible messages the more uncertain of what the actual
> encrypted messages was and there fore the more secure.
No once again you mis the relevant information. All equal sized messages
are equal probable, which means that even though you know the length you do
not get the message.
> Your example of yes or no was a good one. If I ask someone
> a yes or no type of question and the encrypted OTP answer
> comes out as "QW" I think the responce may have been NO.
> While if "ZXV" was the encrypted response I think the
> anwser was YES. If one sent 1000 characters encrypted with
> a OTP you have no idea if he answersed "YES","NO,"MAYBE",
> SOMETIMES",or he may have asked for further clarification.
> I think if you stop to think about it or you can even ask
> Wagner since the source of the response seems to affect you
> more that the truth of it. You may get to finally see the light.
What if I answered in binary?
00 = yes
01 = no
10 = maybe
11 = sometimes.
Nuff said.
Tom
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: Reusing A One Time Pad
Date: Wed, 18 Apr 2001 18:21:50 GMT
"Mark G Wolf" <[EMAIL PROTECTED]> wrote in message
news:9bkksb$7kuu$[EMAIL PROTECTED]...
> > Then it's not an OTP if use reuse the pad. Are you missing the replies
or
> just being plain ignorant?
>
>
> Ok I herby claim a Copyright on the following term for which I wish to be
> credited when it becomes popular because it sounds "fun".
>
> Crypto-Doodle Pad (CDP) - A file consisting of random bits, copies of
which
> are possessed by two or more people, used in conjunction with
cryptological
> algorithms for the exchange of ciphered information.
There is a patent on that already. Not only are you a smart ass you're an
idiot too.
Tom
------------------------------
Date: 18 Apr 2001 18:32:23 -0000
From: [EMAIL PROTECTED] (Fight Boschloo)
Subject: WHY I HATE BOSCHLOO
Crossposted-To: alt.privacy.anon-server,alt.security-pgp
I hate Boschloo
===============================================
HISTORY:
That Boschloo bozo is a clown and a troll who has been looming around for nearly a
year.
Don't mistake a "regular" (troll) with a knowledgeable person: that self-proclaimed
"security expert" is not even a remailer user. In the past, he proved himself unable
to check a PGP signature, and got ridicule from every single technical topic he wante
d to talk about.
Besides false or inaccurate or misleading technical misinformation, his posts are
about his avowed mental illness, or for bashing remops or real freedom fighters: he
likes to quarrel with every one, and stir shit. Sometimes, it is even pure delirium
(whe
n he misses his pills?)
One of his last actions was to stage a hoax about his own suicide, just to try to grab
some sympathy, after he had been exposed as a troll and technically incompetent.
The worst being his teasing of Script-Kiddie until it triggered a new flood on apas.
Of course, he refuses to apologize.
Actually, the level of contempt he shows for remailer users:
they don't give their names, while he does
that can't do anything against him, without giving their names
is in no way different from what is displayed by Pangborn, Burnore and the like
Ignore him completely, killfile him, respect others' killfiles
KILLFILE:
To put him in your killfile, put "Author: Boschloo"
That will make disappear both him and people who warn about him
If you want to tell him to buzz off, or warn about him,
use a nickname containing "Boschloo" (Boschloo Hater, Boschloo Sucks,...)
to accomodate such killfile for "regulars", and still warn newbies
COURAGE:
Boschloo is getting _no_ answer from apas any more.
He has to crosspost to various newsgroups to try to grab some attention.
In a few months, it will be gone.
------------------------------
From: David Schwartz <[EMAIL PROTECTED]>
Crossposted-To: talk.politics.crypto,alt.hacker
Subject: Re: XOR TextBox Freeware: Very Lousy.
Date: Wed, 18 Apr 2001 11:35:30 -0700
Bodo Eggert wrote:
> David Schwartz <[EMAIL PROTECTED]> wrote:
> > the user. If the user had a good, secure means of sending the OTP to the
> > recipient, why wouldn't he just use that mechanism to transfer the
> > plaintext itself?
> The trick is to transfer the random generator or the seed,
> which allows to encrypt a certain (bigger) amount of plaintext.
If you do that, it's not an OTP.
DS
------------------------------
From: Jim Gillogly <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Wed, 18 Apr 2001 11:55:16 -0700
John Savard wrote:
>
> On Tue, 17 Apr 2001 19:57:19 -0300, newbie <[EMAIL PROTECTED]>
> wrote, in part:
>
> >What is yabbing? I did not find it in my humble dictionary
> >I found yaping. Only dog yap. I'm not dog.
> >I'm newbie.
>
> I think he means jabbering, not yapping.
I think he means yabbing, as he said. I did a Google search on the
word, and got lots of hits, each using it in the same sense Tom did,
which I would characterize as you took it: jabbering.
--
Jim Gillogly
Hevensday, 26 Astron S.R. 2001, 17:35
12.19.8.2.12, 13 Eb 10 Pop, Seventh Lord of Night
------------------------------
From: "Tom St Denis" <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Wed, 18 Apr 2001 19:00:08 GMT
"Jim Gillogly" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> John Savard wrote:
> >
> > On Tue, 17 Apr 2001 19:57:19 -0300, newbie <[EMAIL PROTECTED]>
> > wrote, in part:
> >
> > >What is yabbing? I did not find it in my humble dictionary
> > >I found yaping. Only dog yap. I'm not dog.
> > >I'm newbie.
> >
> > I think he means jabbering, not yapping.
>
> I think he means yabbing, as he said. I did a Google search on the
> word, and got lots of hits, each using it in the same sense Tom did,
> which I would characterize as you took it: jabbering.
I dunno if it's a real word... I really meant to say "what are you talking
about" where the length of the message was the real mood... i.e why is this
thread still going on... why can't people just put three ounces of thought
into it...
Tom
------------------------------
From: [EMAIL PROTECTED] (Bill Unruh)
Subject: Re: A practical idea to reinforce passwords
Date: 18 Apr 2001 19:05:14 GMT
In <9bkh4b$2e60$[EMAIL PROTECTED]> "Mark G Wolf"
<[EMAIL PROTECTED]> writes:
]> My idea is that upon selecting a password, X bits of
]> random data is added to the password. You are not
]> informed of what these bits are, nor does the computer
]> store them. The computer only stores how many bits
]> there are, and brute-forces them every time you enter
]> you password.
To brute force, the text needs some sort of predictable clear text, so
you know when you have succeeded in your brute forcing. That of course
also means that the opponent has the same known plaintext to brute force
the whole password against. It is not clear what this procedure is
supposed to accomplish. If the enemy does not know your password, then
he has to brute force the whole thing anyway. What advantage is there to
your know knowing part of your own password?
Note that you can get to know what those extra bits are, ( just write a
little program which does the brute forcing and reports to you). So
what would the advantage be?
]Sounds like a pretty good idea to me. In fact it's something I've been
]thinking about quite a bit lately. The idea that the intended recipient or
]user actually has to do some brute force work to decrypt messages to enhance
]security. In fact I'm often surprised it's not mentioned more often. Gee,
I do not see how it enhances security. If the far side does not know
your key, then he has to brute force the whole thing anyway. If he does,
it is no harder for him than you. Ie, what advantage does your not
knowing what your own key is (in part) give you?
------------------------------
From: "Joseph Ashwood" <[EMAIL PROTECTED]>
Subject: Re: XOR TextBox Freeware: Very Lousy.
Date: Wed, 18 Apr 2001 11:59:02 -0700
Crossposted-To: talk.politics.crypto,alt.hacker
"Bodo Eggert" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> David Schwartz <[EMAIL PROTECTED]> wrote:
>
> > the user. If the user had a good, secure means of sending the OTP to the
> > recipient, why wouldn't he just use that mechanism to transfer the
> > plaintext itself?
>
> The trick is to transfer the random generator or the seed,
> which allows to encrypt a certain (bigger) amount of plaintext.
Wrong. What was being discussed was a OTP. To build a OTP you have to have
as much entropy in the pad as the pad can hold, since your assumption is
that the seed or generator is smaller than the pad the entropy of the
seed/generator must be smaller than the entropy that can be contained in the
pad. It is not a OTP, it will never be a OTP, it can never be a OTP, and
anyone who thinks it's a OTP is incorrect.
Joe
------------------------------
From: Jim Gillogly <[EMAIL PROTECTED]>
Subject: Re: "UNCOBER" = Universal Code Breaker
Date: Wed, 18 Apr 2001 12:13:29 -0700
Tom St Denis wrote:
> I dunno if it's a real word... I really meant to say "what are you talking
> about" where the length of the message was the real mood... i.e why is this
> thread still going on... why can't people just put three ounces of thought
> into it...
In this case, because it just doesn't deserve more than a few grams
of thought. The easy answer is that it's impossible, as people have
correctly pointed out. The practical answer is that it's easier to
build a special-purpose cracker for a specific cipher than a general
one for many ciphers -- I know, because I've done both. My general
one is fine for many (most?) types of classical ciphers. However,
since we don't have practical special-purpose attacks on many of the
modern ciphers, it's way premature to talk about a general attack
that solves all of them.
--
Jim Gillogly
Hevensday, 26 Astron S.R. 2001, 17:35
12.19.8.2.12, 13 Eb 10 Pop, Seventh Lord of Night
------------------------------
From: "M.S. Bob" <[EMAIL PROTECTED]>
Subject: Re: New to cryptography but in need of encryption :o)
Date: Wed, 18 Apr 2001 20:01:46 +0100
Emmanuel Randon wrote:
>
> I am developping for my "end of year" project, a network communication
> software (Windows+VC ++).
> Everything seems to be going fine. Only one part of the project is not clear
> at all. We need to have an encryption capability in it.
> We don't know a lot about cryptography. However we know we would like a
> public algorithm encrypting the key of a private algorithm encrypting the
> message.
> Now the problem is that we don't have any idea of how to start that :o(
I would suggest you use existing protocols and standard algorithms.
Luckily, there are some pretty good choices for free/libre cryptographic
libraries out there.
I would recommend using SSL 3.0/TLS. It is robust, and standard. One of
the most popular free libraries, is OpenSSL (www.openssl.org).
Good luck.
------------------------------
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