Cryptography-Digest Digest #471, Volume #9 Tue, 27 Apr 99 14:13:03 EDT
Contents:
Re: True Randomness & The Law Of Large Numbers (R. Knauer)
new method ? (fgarciau)
Re: Prime Numbers Generator ("Tony T. Warnock")
Re: Prime Numbers Generator ("Tony T. Warnock")
Re: new method ? (Nathan Kennedy)
Re: Prime Numbers Generator (Peter Gunn)
Cryptography FAQ (08/10: Technical Miscellany) ([EMAIL PROTECTED])
Re: Double Encryption is Patented! (from talk.politics.crypto) (John Savard)
Re: Algorithms where encryption=decryption? (John Savard)
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From: [EMAIL PROTECTED] (R. Knauer)
Subject: Re: True Randomness & The Law Of Large Numbers
Date: Tue, 27 Apr 1999 14:18:14 GMT
Reply-To: [EMAIL PROTECTED]
On Tue, 27 Apr 1999 05:38:23 -0700, Jim Gillogly <[EMAIL PROTECTED]> wrote:
>If I see extended plaintext (for some definition of
>extended), I'll expect that it's either real plaintext or fake cover
>traffic.
OK, but which is it?
Bob Knauer
"A fear of weapons is a sign of retarded sexual and emotional maturity."
-- Sigmund Freud
------------------------------
From: fgarciau <[EMAIL PROTECTED]>
Subject: new method ?
Date: Tue, 27 Apr 1999 16:04:07 +0200
Someone told me about a revolutionary (?) method for cryptographie
discovered recently by a teenager girl.
Could you please send me more information about it.
Thank you very much.
Francisco Garcia
email : [EMAIL PROTECTED]
------------------------------
From: "Tony T. Warnock" <[EMAIL PROTECTED]>
Subject: Re: Prime Numbers Generator
Date: Tue, 27 Apr 1999 08:25:03 -0600
Reply-To: [EMAIL PROTECTED]
Phil Howard wrote:
> On Mon, 26 Apr 1999 06:04:12 GMT Douglas A. Gwyn ([EMAIL PROTECTED]) wrote:
>
> | David Kuestler wrote:
> | > Paul Rubin wrote:
> | > > Why not just store a bit map of where the primes are?
> | > > 2^32 possible primes = 2^32 bits = 2^29 bytes = 512 MB.
> | > Good idea ( 2^31 if you only work with the odds = 269MB ).
> |
> | And even better, omit the multiples of 3, 5, 7, 11, etc.
> | :-)
>
> Every block of 30 numbers has no more than 8 primes. That can be
> conveniently recorded in 1 byte. At that point you have 143165577 bytes.
> Getting more multiples in there should shrink it even further, but the
> processing gets to be more complex. Where is the point of diminishing
> returns?
>
I use this method in my number theory calculator. However, it is better to
store the differences in consecutive primes (divided by 2). This will allow
each prime to be only one byte long if x < 19999066711391. The breakeven
point is less than 32767. This would have been more compact and allowed
easier logic.
Tony
------------------------------
From: "Tony T. Warnock" <[EMAIL PROTECTED]>
Subject: Re: Prime Numbers Generator
Date: Tue, 27 Apr 1999 08:26:20 -0600
Reply-To: [EMAIL PROTECTED]
Phil Howard wrote:
> On Mon, 26 Apr 1999 06:04:12 GMT Douglas A. Gwyn ([EMAIL PROTECTED]) wrote:
>
> | David Kuestler wrote:
> | > Paul Rubin wrote:
> | > > Why not just store a bit map of where the primes are?
> | > > 2^32 possible primes = 2^32 bits = 2^29 bytes = 512 MB.
> | > Good idea ( 2^31 if you only work with the odds = 269MB ).
> |
> | And even better, omit the multiples of 3, 5, 7, 11, etc.
> | :-)
>
> Every block of 30 numbers has no more than 8 primes. That can be
> conveniently recorded in 1 byte. At that point you have 143165577 bytes.
> Getting more multiples in there should shrink it even further, but the
> processing gets to be more complex. Where is the point of diminishing
> returns?
>
I use this method in my number theory calculator. However, it is better to
store the differences in consecutive primes (divided by 2). This will allow
each prime to be only one byte long if x < 19999066711391. The breakeven
point is less than 32767. This would have been more compact and allowed
easier logic.
I am going to look into a universal encoding method for compressing these
further. I know that asymptotically universal encoding won't work but it
ought to be good for the first gazillion or so primes, before they get large.
Tony
------------------------------
From: Nathan Kennedy <[EMAIL PROTECTED]>
Subject: Re: new method ?
Date: Tue, 27 Apr 1999 22:21:51 +0800
fgarciau wrote:
>
> Someone told me about a revolutionary (?) method for cryptographie
> discovered recently by a teenager girl.
>
> Could you please send me more information about it.
> Thank you very much.
Media farce. Irish teen girl supposedly comes up with a more efficient
method than RSA. Just the media playing on ignorance to make another big
hype story. Peanuts compared to Y2K.
Nate
------------------------------
From: Peter Gunn <[EMAIL PROTECTED]>
Subject: Re: Prime Numbers Generator
Date: Tue, 27 Apr 1999 15:34:15 +0100
David Kuestler wrote:
> Jim Gillogly wrote
> [snip]
> Excellent ! This ran just shy of an hour on a 233Mhz K6 and gave the
> same file size, though the byte order is different ( as expected ).
> You're certainly a better C programmer than I as you only use integers
> and pointers where as I used array references with the occasional
> floating point operation.
>
> If you are interested you should submit it to The Prime Pages . Your
> code is faster, smaller, more understandable and therefore would be
> easier to impliment than others.
Have a look at http://www.smdp.freeserve.co.uk/erato.cpp
for a somewhat faster version... should run in ~10mins or
less on a 233Mhz PC. Basically it uses bitmaps instead
of character arrays and an 8Mb buffer to speed thing up.
Im sure this could be reduced to less than 2mins runtime
& 1Mb memory usage if it was hacked a bit further.
I suppose you could even use a 2D graphics accelerator
to make things *much* faster? That would be interesting...
might even be worth watching :-)
tata
PG.
PS I took out the code that output the primes to a file :-)
------------------------------
Subject: Cryptography FAQ (08/10: Technical Miscellany)
From: [EMAIL PROTECTED]
Crossposted-To:
alt.gothic,uk.people.gothic,boulder.general,at.test,talk.politics.crypto,sci.answers,news.answers,talk.answers
Date: 27 Apr 1999 00:27:27 GMT
Reply-To: [EMAIL PROTECTED] (Henrietta K. Thomas)
Fuck You If You Aint Goth!!!
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Double Encryption is Patented! (from talk.politics.crypto)
Date: Tue, 27 Apr 1999 14:53:57 GMT
[EMAIL PROTECTED] (John Savard) wrote, in part:
>[EMAIL PROTECTED] (John Savard) wrote, in part:
>>Oh, my. This patent sounds like it covers a technique I was planning to
>>use, although, as someone else noted, it isn't double encryption.
>I should have mentioned that it's U.S. patent 5673319, and it's from 1997.
But it was filed in February 1995, so my first posting of what may be a
similar idea on September 11, 1996 won't cause the patent any problems. Ah,
if only I had gotten on the Internet sooner...
John Savard ( teneerf<- )
http://members.xoom.com/quadibloc/index.html
------------------------------
From: [EMAIL PROTECTED] (John Savard)
Subject: Re: Algorithms where encryption=decryption?
Date: Tue, 27 Apr 1999 17:29:35 GMT
Anne Veling <[EMAIL PROTECTED]> wrote, in part:
>I am looking for any algorithms that can be used in encryption in which
>the encryption algorithm is the same as the decryption algorithm.
Well, the Enigma machine is one famous example of a reciprocal cipher. The
block cipher MAGENTA, entered as an AES candidate, is reciprocal except for
a swap of the halves of the block.
If you're looking for a practical reciprocal cipher, one possibility would
be to use DES, then use an Enigma-machine type cipher with a 256-character
alphabet, then decipher with DES with the same key. This should be secure
despite being reciprocal.
John Savard ( teneerf<- )
http://members.xoom.com/quadibloc/index.html
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