Algorithm from easy spec please!

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Kenneth N Macpherson

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Jun 15, 1999, 3:00:00 AM6/15/99
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Hello,

If someone knows of a way to do this I would be grateful!

Need to take the numbers 32 to 126 inclusive and insert them into an array
randomly based on a key (of numbers).

The numbers in the key will all be in the range 32 to 126.

It is a simple lookup table.

Pseudo code would be brilliant and vb code would be fantastic!

Thanks in advance,

Cheers,

Ken

Mok-Kong Shen

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Jun 15, 1999, 3:00:00 AM6/15/99
to Kenneth N Macpherson
Kenneth N Macpherson wrote:

>
> Need to take the numbers 32 to 126 inclusive and insert them into an array
> randomly based on a key (of numbers).
>
> The numbers in the key will all be in the range 32 to 126.
>
> It is a simple lookup table.
>
> Pseudo code would be brilliant and vb code would be fantastic!

Fill your array with the numbers 32 to 126 consecutively. Then
use a pseudo-random number generator delivering real-valued numbers
in [0,1) to perform a random permutation using the algorithm
of Dustenfeld (see Knuth's book, vol. 2).

M. K. Shen

tomst...@my-deja.com

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Jun 15, 1999, 3:00:00 AM6/15/99
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<snip>

Here is my idea.

1. Create 16 tables which are substitution tables. So they contain
each char once, and only once (it has to be invertible). Each table
will be different but keyed from the master key somehow.

2. Create an 16 element array of the numbers 0..15. This too will be
shuffled using the key.

3. Take your range 33-126 and convert it to 0-93 by subtracting 33 from
each input char.

4. Take this char and run it thru all the substituion tables use the
order as created in #2. So you take the char and use it as an index
into the tables recursively. The #2 array will determine the
substitution table order usage.

5. Swap two elements of array #2

6. Goto #3 as required.

To decrypt you will run the chars backwards and perform the same
operations.

I will leave it as an execise for you to figure out how to key the
tables. HINT #2 can be done using the RC4 shuffle.

This should provide about as much security as you said you need. With
16 tables you can encode 2^44 chars which I think is enough for your
purposes. The keysize is small but the average job blow probably will
not be able to brute force it. (If you need to enhance it use a larger
data space).

Tom


Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

Jim...@postmaster.co.uk

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Jun 15, 1999, 3:00:00 AM6/15/99
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Ok, if you already have a RNG that is strong enough for you,


int table[93], table2[93];

for(i=0;i<93;i++)
table[i]=i;

table is now full of intergers 0-93.

assuming the nos in the key are 0-93 (ie your key -33) -- all of them,
no duplicates,

for(i=0;i<93;i++)
table2[i]=table[ key[i] ];


table2 is now randomly full of 0-93, keyed by your key. The code is
odd C (i am not a programmer really...), but i _think_ the principle
is sound and quick.

Jerry Coffin

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Jun 15, 1999, 3:00:00 AM6/15/99
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In article <929458378.26401.0...@news.demon.co.uk>,
ke...@geharris.co.uk says...

> Hello,
>
> If someone knows of a way to do this I would be grateful!
>
> Need to take the numbers 32 to 126 inclusive and insert them into an array
> randomly based on a key (of numbers).
>
> The numbers in the key will all be in the range 32 to 126.
>
> It is a simple lookup table.
>
> Pseudo code would be brilliant and vb code would be fantastic!

There are a number of ways, but one that combines simplicity with a
reasonable degree of efficiency is to insert the numbers into the
array in order, then scramble them using a random number generator.
You use the key as the seed to the random number generator. Here's
some pseudo-code:

srand(seed) ' seed the random number generator

for I = 32 to 126
array[I] = I
next

for I = 126 to 33 step -1
x = rand(33, x)
if x <> I
temp = array[I]
array[I] = array[x]
array[x] = temp
endif
next

in this case, rand(x, y) is a function that returns a random number
between x and y inclusive. IIRC, VB's random number generator
normally returns floating point values between 0 and 1, so to get
this, you'd do something like:

integer function random(lower%, upper%)
range% = upper%-lower%

return range% * random(0) + lower%
end function

Note that this will generally introduce some bias -- I.e. some values
are marginally more likely to occur than others. Given that you're
posting this in sci.crypt, I'm guessing that this doesn't matter a lot
to you -- if you're using this for a simple substitution cipher, the
result is going to be quite weak in any cse, so a minor shortcoming in
the random number generation probably isn't going to make a lot of
difference to you regardless.

wtshaw

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Jun 15, 1999, 3:00:00 AM6/15/99
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In article <929458378.26401.0...@news.demon.co.uk>, "Kenneth
N Macpherson" <ke...@geharris.co.uk> wrote:

> Hello,
>
> If someone knows of a way to do this I would be grateful!
>
> Need to take the numbers 32 to 126 inclusive and insert them into an array
> randomly based on a key (of numbers).
>
> The numbers in the key will all be in the range 32 to 126.
>
> It is a simple lookup table.
>
> Pseudo code would be brilliant and vb code would be fantastic!
>

> Thanks in advance,
>
> Cheers,
>
> Ken

Talking of keyboards, someone posted a simple system with the
you-can't-solve-it tag in which keys adjacent of the plaintext keys were
pressed in a pattern. Taking the basic idea, I implemented and added to
it.

Figure the you have 47 keys, and have two cases for each. If you allow the
case and spaces to pass through, you do leak some of the plaintext, but
still have an interesting result. For this example, I use an 47 character
alphabet taken directly from the keyboard, left to right, top to bottom.

The key is composed of a single reference character followed by other
characters; convert this to a series of offsets. My key can be from 2 to
47 characters.

Encrypt by finding the plaintext character, adding the current offset, and
getting the ciphertext characters. Simple enough?

This sentence is the key. The above couple of lines are simply encrypted
to be what follows. Notice that each time a T, the reference character,
is repeated in the key, the plaintext and ciphertext characters are the
same. Naturally, 47 keys would produce the same encryption since any of
the 47 could be the reference character.

F.2ar`t cm 4y.xi9d kfr $1fg5evxe t6]u'chqjn s)n[5v e9e z,xwy5t ;s.\r?- f5x
dvte.td ibe 6yxfr>hy1s z9aw4weyas= |'b[Rf y5ht8h<

This is really just based on a simple slide cipher. My version does other
sized alphabets as well, 26, 30, 40, 47, so the sourcecode reflects that.
I did not mess with random deranged alphabets or keys, but those could be
a additional complication.

The FutureBasic Sourcecode probably would not be too helpful to you, about
15K in the single textfile which yields a fully implemented GUI
application for a 68K Mac. The big trick in functional crypto is to get a
shell for programs that works for you on your platform with a simple
algorithm, then modify. Once the simple things like this algorithm are
shown to work, you can get into more complicated ones.
--
More is less.

Jim Gillogly

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Jun 15, 1999, 3:00:00 AM6/15/99
to
John Markoff has written an article at the NY Times site about
the Kryptos sculpture: www.nytimes.com in the Technology section.
You might enjoy using the known plaintext there to see how the
three ciphers that I decrypted were constructed. Note that the
third cryptogram's plaintext should have a "Q" added at the end
before the question mark. I was interested when I called the
CIA Public Affairs office last week to learn that it had previously
been partly solved inside the intelligence community.

Neither I nor the other solvers (a team of three NSA cryppies
and a non-cryptographer CIA analyst, working separately) have
yet been able to solve the last 97 characters:

OBKR
UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO
TWTQSJQSSEKZZWATJKLUDIAWINFBNYP
VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR

There aren't many repeats of note, and if there's any periodicity
it's pretty grotesque (i.e. period 25). I suspect running key,
or perhaps a combination polyalphabetic substitution and permutation,
or perhaps an autokey of some sort. I think it is keyed rather than
a OTP because in one of the old articles Sanborn, the sculptor, says
the mysterious envelope delivered to the Director of Central Intelligence
contains the keys to the sculpture, and that with those the DCI could
decrypt it easily.
--
Jim Gillogly
26 Forelithe S.R. 1999, 05:07
12.19.6.5.1, 5 Imix 9 Zotz, Second Lord of Night

Kenneth N Macpherson

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Jun 16, 1999, 3:00:00 AM6/16/99
to
Thanks for all of the suggestions - here are some additional comments.

The key will be 14 chars long and may contain duplicates but all will be in
range 32 to 126.

I like the random number swapping idea using the key to seed the generator
but, will seed X on machine A produce the same random sequence as seed X on
machine B?

Thanks,

Ken

Kenneth N Macpherson

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Jun 16, 1999, 3:00:00 AM6/16/99
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A method of scrambling the consecutive numbers using the key but not using
pseudo random sequence would be good as I am not sure that 2 different
machines will produce the same sequence when seeded with the same key.

Ken

Mok-Kong Shen

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Jun 16, 1999, 3:00:00 AM6/16/99
to

It is not possible by 'logic' to scramble without using something
'random'. PRNGs are mostly based on integer arithmetics and then
converted to reals. If you use the same high-level code, you are
sure to get the same result in view of the very small range of
values of your application, i.e. the accuracy problem in relation
to portability is not non-existant in general but is not relevant
for your case.

M. K. Shen

John Savard

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Jun 16, 1999, 3:00:00 AM6/16/99
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Jim Gillogly <j...@acm.org> wrote, in part:

>I think it is keyed rather than
>a OTP because in one of the old articles Sanborn, the sculptor, says
>the mysterious envelope delivered to the Director of Central Intelligence
>contains the keys to the sculpture, and that with those the DCI could
>decrypt it easily.

Although I think you're right, since there would seem no point in
putting an OTP-encrypted message on such a sculpture, I fear that many
would quibble with the specific reason you've given: one certainly
*can* put the key to an OTP-encrypted message in an envelope, and such
a message can be decrypted easily with that key just like any other
encrypted message.

John Savard ( teneerf<- )
http://members.xoom.com/quadibloc/crypto.htm

Douglas A. Gwyn

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Jun 17, 1999, 3:00:00 AM6/17/99
to
Jim Gillogly wrote:
> ... the last 97 characters:OBKR
> UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO
> TWTQSJQSSEKZZWATJKLUDIAWINFBNYP
> VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR

> I think it is keyed rather than
> a OTP because ...

Notice its monographic IC is less
than 1, i.e. it is flatter than
uniform-random, but not so much
so that much significance can be
attributed to the fact. That
makes me suspect autokey, also.

Andreas Bogk

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Jun 18, 1999, 3:00:00 AM6/18/99
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jsa...@tenMAPSONeerf.edmonton.ab.ca (John Savard) writes:

> Although I think you're right, since there would seem no point in
> putting an OTP-encrypted message on such a sculpture, I fear that many
> would quibble with the specific reason you've given: one certainly
> *can* put the key to an OTP-encrypted message in an envelope, and such
> a message can be decrypted easily with that key just like any other
> encrypted message.

And that key could be buried at the location specified in section 2 of
the text. Anybody cared to dig there yet? I think section 3 could be a
clue that this is indeed the right approach.

Andreas

--
Reality is two's complement. See:
ftp://ftp.netcom.com/pub/hb/hbaker/hakmem/hacks.html#item154

Jim Gillogly

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Jun 18, 1999, 3:00:00 AM6/18/99
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Andreas Bogk wrote:
> And that key could be buried at the location specified in section 2 of
> the text. Anybody cared to dig there yet? I think section 3 could be a
> clue that this is indeed the right approach.

The coordinates appear to be at CIA HQ, despite the fact that MapBlast
shows it as being in Maryland. It's been speculated that there's a
time capsule or other such object buried in the slabs under the sculpture
itself. I don't recommend people wandering up the CIA offramp with pick
and shovel, though: they're notoriously a bit sensitive about that kind
of thing, and besides, the NSA has had the decryption since late 1992.

I just got the OK from the NSA Public Affairs Office to mention that,
by the way: a team of NSA cryppies working in their off hours spent
most of 1992 on it, finally getting all but the famous final 97 characters
near the end of the year. There names are still shrouded in mystery, as
you might guess.

--
Jim Gillogly
Trewesday, 28 Forelithe S.R. 1999, 23:48
12.19.6.5.3, 7 Akbal 11 Zotz, Fourth Lord of Night

Douglas A. Gwyn

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Jun 20, 1999, 3:00:00 AM6/20/99
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Jim Gillogly wrote:
> by the way: a team of NSA cryppies working in their off hours spent
> most of 1992 on it, finally getting all but the famous final 97
> characters near the end of the year. There names are still shrouded
> in mystery, as you might guess.

The actual problem is that there is still a law on the books that makes
it a Federal felony to publish the names of IC members. The law was
passed in an attempt to stop anti-war protesters from setting up CIA
employees as targets of retribution, which they had been doing.
The IC applied the law over-zealously, to the extent that several years
ago when I called the NSA switchboard to be connected to a certain
employee that I knew worked there, the operator said that she could
neither confirm nor deny that any such person worked there, thus they
couldn't patch me through to a name, just to a phone number, which I
could of course direct-dial if I knew it! Made me wonder just why they
bothered to staff the switchboard at all.

Paul Rubin

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Jun 20, 1999, 3:00:00 AM6/20/99
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Douglas A. Gwyn <DAG...@null.net> wrote:
>The actual problem is that there is still a law on the books that makes
>it a Federal felony to publish the names of IC members. The law was
>passed in an attempt to stop anti-war protesters from setting up CIA
>employees as targets of retribution, which they had been doing.
>The IC applied the law over-zealously, to the extent that several years
>ago when I called the NSA switchboard to be connected to a certain
>employee that I knew worked there, the operator said that she could
>neither confirm nor deny that any such person worked there, thus they
>couldn't patch me through to a name, just to a phone number, which I
>could of course direct-dial if I knew it! Made me wonder just why they
>bothered to staff the switchboard at all.

LOL! It was just a few years ago that NSA staff started showing
up at crypto conferences with "NSA" on their name badges. Before
that they always just said "Department of Defense".

Renegade

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Jun 22, 1999, 3:00:00 AM6/22/99
to
> I just got the OK from the NSA Public Affairs Office to mention that,
> by the way: a team of NSA cryppies working in their off hours spent
> most of 1992 on it, finally getting all but the famous final 97 characters
> near the end of the year. There names are still shrouded in mystery, as
> you might guess.

This is another example of how the NSA/IC is years ahead of the private
sector, and operates in complete silence about their accomplishments
(granted, this was a private accomplishment, which only makes it more
interesting that they could have come public and still chose not to).

-Mike

Douglas A. Gwyn

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Jun 23, 1999, 3:00:00 AM6/23/99
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Renegade wrote:
> This is another example of how the NSA/IC is years ahead of the
> private sector, ...

While I would agree with that in many cases, I suspect the Kryptos
cracking was done with pretty much the same technology and skills
that were applied by Gillogly. The CIA cracker is said to have
done it as mainly a pencil-and-paper exercise, and perhaps the NSA
cryppies tackled it on the same terms. (That would explain why it
took them so long!)

Jerry Coffin

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Jun 23, 1999, 3:00:00 AM6/23/99
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In article <3770B4AE...@null.net>, DAG...@null.net says...

I think in this case, their cracking it long before the rest of us
mostly had to do with their having easy access to it before the rest
of us did. I'm not sure when Jim started working on the problem, but
from what he's said, it sounds like once he started working on it, he
cracked it in less time than they did...

Douglas A. Gwyn

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Jun 24, 1999, 3:00:00 AM6/24/99
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Jerry Coffin wrote:
> I think in this case, their cracking it long before the rest of us
> mostly had to do with their having easy access to it before the rest
> of us did. I'm not sure when Jim started working on the problem, but
> from what he's said, it sounds like once he started working on it, he
> cracked it in less time than they did...

Since I posted an accurate transcript of the Kryptos ciphertext
several years ago, there has been plenty of time to work on it.
(ACA's The Cryptogram published a slightly incomplete and slightly
inaccurate version in the MA92 issue, which was the start of my
quest for the complete, accurate text.)

Jim took about 9 days, I think, not counting a preliminary
glance at it earlier and his previous investment in constructing
general cryptanalytic tools (computer and otherwise). Also not
counting the time previously invested in learning and practicing
cryptanalysis. (Practice is more important than you might think.)

I think there are several other people who *could* have cracked
Kryptos to the same degree, but didn't have the motivation or time.

It would be nice if somebody would get that last piece of Kryptos
deciphered.

Jim Gillogly

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Douglas A. Gwyn wrote:
> Jerry Coffin wrote:
> > I think in this case, their cracking it long before the rest of us
> > mostly had to do with their having easy access to it before the rest
> > of us did. I'm not sure when Jim started working on the problem, but
> > from what he's said, it sounds like once he started working on it, he
> > cracked it in less time than they did...
>
> Since I posted an accurate transcript of the Kryptos ciphertext
> several years ago, there has been plenty of time to work on it.
> (ACA's The Cryptogram published a slightly incomplete and slightly
> inaccurate version in the MA92 issue, which was the start of my
> quest for the complete, accurate text.)
>
> Jim took about 9 days, I think, not counting a preliminary
> glance at it earlier and his previous investment in constructing
> general cryptanalytic tools (computer and otherwise). Also not
> counting the time previously invested in learning and practicing
> cryptanalysis. (Practice is more important than you might think.)

I took four evenings: the posting by uhussy that triggered the
thread was on 6 Jun. Tom's article that I felt obliged to correct
was on 7 Jun; I corrected it that day and started working on it
again that evening (I'd looked at it briefly in 1992 and again a
couple times over the years). My first break was announced here
on the 8th, and I solved the transposition on the evening of the
10th, before my chamber music group's dress rehearsal. The NSA
team spent most of 1992 on it, finishing it (except for the same
old 97 Letters o' Doom at the end) near the end of the year,
according to Judy Emmel at NSA. Stein took 400 hours, by his
estimate.

> I think there are several other people who *could* have cracked
> Kryptos to the same degree, but didn't have the motivation or time.

Each of the systems so far would be solvable by most ACA members
with sufficient time, if armed with the knowledge that it was in
fact solvable. A positive mental attitude is a real key to this
kind of thing. The transposition would have taken me much longer
without my programs; but a '386 would have been nearly as effective
as my P2/400 for this task... assuming it ran Linux, of course.

> It would be nice if somebody would get that last piece of Kryptos
> deciphered.

Absolutely! And after that we can start on the meta-puzzle.
--
Jim Gillogly
1 Afterlithe S.R. 1999, 10:57
12.19.6.5.9, 13 Muluc 17 Zotz, First Lord of Night

Michael

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Douglas A. Gwyn wrote:
[snip]
> Since I posted an accurate transcript of the Kryptos ciphertext
> several years ago, there has been plenty of time to work on it.
> (ACA's The Cryptogram published a slightly incomplete and slightly
> inaccurate version in the MA92 issue, ...
[snip]


Which is the problem I encountered. Before starting any work on the
"Famous 97 Characters" I tried to verify that I had the correct,
complete, cipher text. I might ..... don't really know for sure. Of
the 4 copies the cipher text I was able to dig up, 3 have different
lengths. Is the accurate transcript you spoke of here currently posted
somewhere on the Web?

--
Michael
---
NOTE: Reply_To has been forged to foil SPAM.
Please reply via this NewsGroup.

Jim Gillogly

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Michael wrote:
> Douglas A. Gwyn wrote:
> [snip]
> > Since I posted an accurate transcript of the Kryptos ciphertext
> > several years ago, there has been plenty of time to work on it.
> > (ACA's The Cryptogram published a slightly incomplete and slightly
> > inaccurate version in the MA92 issue, ...
> [snip]
>
> Which is the problem I encountered. Before starting any work on the
> "Famous 97 Characters" I tried to verify that I had the correct,
> complete, cipher text. I might ..... don't really know for sure. Of
> the 4 copies the cipher text I was able to dig up, 3 have different
> lengths. Is the accurate transcript you spoke of here currently posted
> somewhere on the Web?

It is now -- see below. This is the version I used to crack the first
N-97 letters. There are two typos in the substitution section, but they
are cut into the KRYPTOS sculpture itself, and may be meaningful: the
erroneous ciphertext letters are K and R (the first letters of KRYPTOS),
and the erroneous plaintext letters are Q and U (replacing L and O).
Whenever I see QU in the same breath I get suspicious. There's also
a misspelling in the transposition section: an A that should be an E,
and an omitted E in the same word. That could extend QU into QUA if
it's meaningful.

In addition, I've just been told that some of the letters on the sculpture
are in italics. I hope to learn soon which ones they are.

Finally, I note that the Today Show didn't run the KRYPTOS segment
today after all. I imagine David Stein and his family had to watch
the ABC Evening News for nearly a year before his interview was aired,
so I guess I'll put my VCR on automatic and wait for reports.

----------------------Forwarded message ------------------------

From: gw...@smoke.brl.mil (Doug Gwyn)
Subject: corrected Kryptos transcription
Keywords: CIA Kryptos sculpture cipher transcription update
Date: 1 Sep 92 17:28:04 GMT
Organization: U.S. Army Ballistic Research Lab (BRL), APG, MD.

EMUFPHZLRFAXYUSDJKZLDKRNSHGNFIVJ ABCDEFGHIJKLMNOPQRSTUVWXYZABCD
YQTQUXQBQVYUVLLTREVJYQTMKYRDMFD AKRYPTOSABCDEFGHIJLMNQUVWXZKRYP
VFPJUDEEHZWETZYVGWHKKQETGFQJNCE BRYPTOSABCDEFGHIJLMNQUVWXZKRYPT
GGWHKK?DQMCPFQZDQMMIAGPFXHQRLG CYPTOSABCDEFGHIJLMNQUVWXZKRYPTO
TIMVMZJANQLVKQEDAGDVFRPJUNGEUNA DPTOSABCDEFGHIJLMNQUVWXZKRYPTOS
QZGZLECGYUXUEENJTBJLBQCRTBJDFHRR ETOSABCDEFGHIJLMNQUVWXZKRYPTOSA
YIZETKZEMVDUFKSJHKFWHKUWQLSZFTI FOSABCDEFGHIJLMNQUVWXZKRYPTOSAB
HHDDDUVH?DWKBFUFPWNTDFIYCUQZERE GSABCDEFGHIJLMNQUVWXZKRYPTOSABC
EVLDKFEZMOQQJLTTUGSYQPFEUNLAVIDX HABCDEFGHIJLMNQUVWXZKRYPTOSABCD
FLGGTEZ?FKZBSFDQVGOGIPUFXHHDRKF IBCDEFGHIJLMNQUVWXZKRYPTOSABCDE
FHQNTGPUAECNUVPDJMQCLQUMUNEDFQ JCDEFGHIJLMNQUVWXZKRYPTOSABCDEF
ELZZVRRGKFFVOEEXBDMVPNFQXEZLGRE KDEFGHIJLMNQUVWXZKRYPTOSABCDEFG
DNQFMPNZGLFLPMRJQYALMGNUVPDXVKP LEFGHIJLMNQUVWXZKRYPTOSABCDEFGH
DQUMEBEDMHDAFMJGZNUPLGEWJLLAETG MFGHIJLMNQUVWXZKRYPTOSABCDEFGHI

ENDYAHROHNLSRHEOCPTEOIBIDYSHNAIA NGHIJLMNQUVWXZKRYPTOSABCDEFGHIJ
CHTNREYULDSLLSLLNOHSNOSMRWXMNE OHIJLMNQUVWXZKRYPTOSABCDEFGHIJL
TPRNGATIHNRARPESLNNELEBLPIIACAE PIJLMNQUVWXZKRYPTOSABCDEFGHIJLM
WMTWNDITEENRAHCTENEUDRETNHAEOE QJLMNQUVWXZKRYPTOSABCDEFGHIJLMN
TFOLSEDTIWENHAEIOYTEYQHEENCTAYCR RLMNQUVWXZKRYPTOSABCDEFGHIJLMNQ
EIFTBRSPAMHHEWENATAMATEGYEERLB SMNQUVWXZKRYPTOSABCDEFGHIJLMNQU
TEEFOASFIOTUETUAEOTOARMAEERTNRTI TNQUVWXZKRYPTOSABCDEFGHIJLMNQUV
BSEDDNIAAHTTMSTEWPIEROAGRIEWFEB UQUVWXZKRYPTOSABCDEFGHIJLMNQUVW
AECTDDHILCEIHSITEGOEAOSDDRYDLORIT VUVWXZKRYPTOSABCDEFGHIJLMNQUVWX
RKLMLEHAGTDHARDPNEOHMGFMFEUHE WVWXZKRYPTOSABCDEFGHIJLMNQUVWXZ
ECDMRIPFEIMEHNLSSTTRTVDOHW?OBKR XWXZKRYPTOSABCDEFGHIJLMNQUVWXZK
UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO YXZKRYPTOSABCDEFGHIJLMNQUVWXZKR
TWTQSJQSSEKZZWATJKLUDIAWINFBNYP ZZKRYPTOSABCDEFGHIJLMNQUVWXZKRY
VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR ABCDEFGHIJKLMNOPQRSTUVWXYZABCD

? are actual question-mark characters

transcribed from photos by PHOENIX, published in The Cryptogram MA92
retyped into this machine-readable file by Doug Gwyn
slight edits made by Gwyn based on CNN video supplied by Harry Carter
resulting draft visually checked on site and corrected by Gwyn
Gwyn's estimate of probability of any residual transcription error: 0.6

---------------End forwarded message---------------------------------
--
Jim Gillogly
1 Afterlithe S.R. 1999, 14:13

Renegade

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Jun 24, 1999, 3:00:00 AM6/24/99
to
> > Renegade wrote:
> > > This is another example of how the NSA/IC is years ahead of the
> > > private sector, ...
> >
> > While I would agree with that in many cases, I suspect the Kryptos
> > cracking was done with pretty much the same technology and skills
> > that were applied by Gillogly. The CIA cracker is said to have
> > done it as mainly a pencil-and-paper exercise, and perhaps the NSA
> > cryppies tackled it on the same terms. (That would explain why it
> > took them so long!)

What I really meant was not the technical ability, but the fact that they
did it and chose to remain silent for years, on a clearly unclassified
problem.

>
> I think in this case, their cracking it long before the rest of us
> mostly had to do with their having easy access to it before the rest
> of us did

Yes, this is true. And from what I recall, Jim solved it in less than 10
days, quite an accomplishment, and "10 days" is the better number to use as
a reference.

During the NBA game I saw reference to a possible Today Show segment that
would air this am, but missed it. Did anyone see it?

Jim Gillogly

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Renegade wrote:
> Yes, this is true. And from what I recall, Jim solved it in less than 10
> days, quite an accomplishment, and "10 days" is the better number to use as
> a reference.

Four evenings, actually. I've spent quite a few hours since then trying
to solve the fourth segment, with no progress worth noting... just a few
possible statistical anomalies for which I'm trying to construct models.
The danged thing is so short!

> During the NBA game I saw reference to a possible Today Show segment that
> would air this am, but missed it. Did anyone see it?

They bumped it because of a KKK trial that ended recently. The current
tentative air date is tommorow (Friday); no more specific time yet. With
any luck my Dundee Marmalade crock will be visible next to my elbow. No,
I'm not a member of the Dundee Society -- this was a case of "If you buy
an outfit you can be a cowboy too."

My wife thought the gorilla banging on the window at the Bronx Zoo on the
Today Show looked rather like me. I acknowledged the resemblance, but
pointed out that it had more hair on top than I do, and she was forced to
recant.

--
Jim Gillogly
1 Afterlithe S.R. 1999, 18:25

Douglas A. Gwyn

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Jim Gillogly wrote:
> Each of the systems so far would be solvable by most ACA members
> with sufficient time, if armed with the knowledge that it was in
> fact solvable. A positive mental attitude is a real key to this
> kind of thing.

I agree, and it is a point driven home by MilCryp and the Zendian
problem.

Douglas A. Gwyn

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Jun 24, 1999, 3:00:00 AM6/24/99
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Jim Gillogly wrote:
> In addition, I've just been told that some of the letters on the
> sculpture are in italics.

Hm, you'd think I would have noticed something like that.

Now that we know where the real "message breaks" are,
I wonder if there is any indication of them on the sculpture,
such as a slightly wider inter-letter spacing or whatever.

Douglas A. Gwyn

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Jim Gillogly wrote:
> With any luck my Dundee Marmalade crock will be visible next to my
> elbow. No, I'm not a member of the Dundee Society -- this was a
> case of "If you buy an outfit you can be a cowboy too."

I suspect you're going to have to explain that (and maybe the outfit
reference as well) to many of the readers.

Even though LDC hasn't been with us for many years now, the Dundee
Society seems to live on, or at least have a room reserved for it --
there's a pointer sign for it in the HQ cafeteria.

Jim Gillogly

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Jun 24, 1999, 3:00:00 AM6/24/99
to
"Douglas A. Gwyn" wrote:
> Jim Gillogly wrote:
> > With any luck my Dundee Marmalade crock will be visible next to my
> > elbow. No, I'm not a member of the Dundee Society -- this was a
> > case of "If you buy an outfit you can be a cowboy too."
>
> I suspect you're going to have to explain that (and maybe the outfit
> reference as well) to many of the readers.

I'll explain the "outfit" bit if you'll go into greater detail on Dundee.
The Smothers Brothers, a popular comedy duo of my youth, had a song that
went something like:

As I was out walking in the streets of Laredo,
As I was out walking in Laredo one day,
I spied a young cowboy all dressed in white linen,
Dressed in white linen as cold as the clay.

Tom: "I see by your outfit that you are a cowboy."
Dick: "I see by your outfit that you're a cowboy, too."
Both: "We see by our outfits that we are both cowboys."
Looking at audience: "If you buy an outfit you can be a cowboy too."

> Even though LDC hasn't been with us for many years now, the Dundee
> Society seems to live on, or at least have a room reserved for it --
> there's a pointer sign for it in the HQ cafeteria.

From stories leaking out of the Fort, it seems that Lambros D. Callimahos,
main author of the indispensible Military Cryptanalytics, was the founder of
the Dundee Society, of which all students of his advanced course were
automatically members. It was named after the James Keiller & Sons Dundee
Orange Marmalade crock in which he kept his pencils; I don't know what it
looked like, since there have been around a dozen styles over the years.
Evidently he was quite eccentric, and perhaps went overboard in doing
more and more detailed background for the Zendian Problem, one of the
primary study sets for the advanced cryptanalysis course. I would guess
it's the same syndrome experienced by serious D&D dungeonmasters. Having
pretty much finished the Zendian Problem, I figured if I were going to be
a serious amateur cryppie, I'd need a Dundee crock... my "outfit", as it
were. E-Bay obliged with an antique one.

More details, please?
--
Jim Gillogly
1 Afterlithe S.R. 1999, 23:37

Michael

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Jun 24, 1999, 3:00:00 AM6/24/99
to
Jim Gillogly wrote:

>
> Michael wrote:
> Is the accurate transcript you spoke of here currently posted
> > somewhere on the Web?
>
> It is now --
> Jim Gillogly
> 1 Afterlithe S.R. 1999, 14:13

> 12.19.6.5.9, 13 Muluc 17 Zotz, First Lord of Night


Many thanks, Jim. Guess we know what I'll be doing this weekend ...
after mowing the lawn.

rrid...@my-deja.com

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Jun 25, 1999, 3:00:00 AM6/25/99
to
Jim is your program available? If not will you
make it so? Done in perl?


Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

Douglas A. Gwyn

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Jun 25, 1999, 3:00:00 AM6/25/99
to
Jim Gillogly wrote:
> From stories leaking out of the Fort, it seems that Lambros D.
> Callimahos, main author of the indispensible Military Cryptanalytics,
> was the founder of the Dundee Society, of which all students of his
> advanced course were automatically members. It was named after the
> James Keiller & Sons Dundee Orange Marmalade crock in which he kept
> his pencils; I don't know what it looked like, since there have been
> around a dozen styles over the years. Evidently he was quite
> eccentric, and perhaps went overboard in doing more and more detailed
> background for the Zendian Problem, one of the primary study sets for
> the advanced cryptanalysis course. I would guess it's the same
> syndrome experienced by serious D&D dungeonmasters. Having pretty
> much finished the Zendian Problem, I figured if I were going to be
> a serious amateur cryppie, I'd need a Dundee crock... my "outfit", as
> it were. E-Bay obliged with an antique one.

If anybody is entitled to honorary membership, it would be Jim.

> More details, please?

That's essentially all there is to that story, except I haven't heard
that LDC was particularly "eccentric". (That rumor may have originated
in NSA's attempt to distance themselves from his work on communication
with extraterrestrial intelligence, which he seems to have gotten
started on as an invited participant in a colloquium or Senate hearing.
I have those documents and plan to put them up on my Web site, if I
ever get it going. Some of them are available as bitmaps on the NSA's
site in the FOIA released-document section.) I think the DS held
occasional meetings, just so these people could chat about their common
interest.

LDC wrote many tutorial articles for the NSA Tech. J. (later the
Cryptologic Quarterly) and as monographs on "classical" C/A topics
(as opposed to advanced mathematical methods), many of which were
assembled into a third Part of MilCryp, most of which remains
classified (wrongly, in my opinion, but I have to abide by the rules).
John Gilmore (EFF) got a heavily redacted version released via the
FOIA, a copy of which is in the National Cryptologic Museum's library,
but the released portions don't say much that isn't available from
other sources (which is probably why they were considered releasable).
There were going to be several additional Parts of MilCryp, as listed
in the published volumes, but LDC died before they were completed.

LDC was also a professional concert flautist (what do you call a
piccolo-ist?), and last time I looked, one of his recordings was
still available on CD-ROM.

John Savard

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Jun 25, 1999, 3:00:00 AM6/25/99
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Jim Gillogly <j...@acm.org> wrote, in part:

>Having


>pretty much finished the Zendian Problem, I figured if I were going to be
>a serious amateur cryppie, I'd need a Dundee crock... my "outfit", as it
>were. E-Bay obliged with an antique one.

Except to do some preliminary sorting out of the information that
seems to identify messages, and to find some that were similar, I
haven't started. But I did find, in a local thrift shop one day (hey,
more recently I found a pair of Maggies there) a jar of the kind that
was of opaque light brown glass or ceramic - although it does vary
from "authenticity" in one way, being bilingual.

Jim Gillogly

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Jun 25, 1999, 3:00:00 AM6/25/99
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rrid...@my-deja.com wrote:
> Jim is your program available? If not will you
> make it so? Done in perl?

No, sorry. If you'd like to learn how to do this sort of
stuff, I recommend the American Cryptogram Association:

ACA Treasurer
1118 Via Palo Alto
Aptos CA 95003.

I use Perl for one-off programs and things that aren't computationally
intensive -- analyzing and diagnosing unknowns, for example. C is
better for the serious crunching, like if you want to do an N^2 search
on a word list for an autokey primer and alphabet key; or for the kind
of hill-climbing approaches to which I've become addicted for classical
ciphers.

--
Jim Gillogly
2 Afterlithe S.R. 1999, 17:00
12.19.6.5.10, 1 Oc 18 Zotz, Second Lord of Night

Lincoln Yeoh

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Jun 25, 1999, 3:00:00 AM6/25/99
to
On Thu, 24 Jun 1999 22:38:15 GMT, "Douglas A. Gwyn" <DAG...@null.net>
wrote:

>Jim Gillogly wrote:

http://www.odci.gov/cia/information/tour/krypt.html

Is that a hole on the lower right? And is that where we're supposed to dig
or look inside?

Link.
****************************
Reply to: @Spam to
lyeoh at @peo...@uu.net
pop.jaring.my @
*******************************

Jim Gillogly

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Jun 25, 1999, 3:00:00 AM6/25/99
to
Lincoln Yeoh wrote:
> http://www.odci.gov/cia/information/tour/krypt.html
>
> Is that a hole on the lower right? And is that where we're supposed to dig
> or look inside?

It's a pool of water. I suspect if you stand a bit closer it would
reflect the Vigenere table that's cut through the copper panels on
the right; we're seeing them reversed, so presumably the pool will
straighten them out for us.

Is there another pool on the concave side of the cipher panels?

--
Jim Gillogly
2 Afterlithe S.R. 1999, 19:14

Jim Gillogly

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Jun 25, 1999, 3:00:00 AM6/25/99
to
Jim Gillogly wrote:
>
> Lincoln Yeoh wrote:
> > http://www.odci.gov/cia/information/tour/krypt.html
> >
> > Is that a hole on the lower right? And is that where we're supposed to dig
> > or look inside?
>
> It's a pool of water. I suspect if you stand a bit closer it would
> reflect the Vigenere table that's cut through the copper panels on
> the right; we're seeing them reversed, so presumably the pool will
> straighten them out for us.

Reflecting on this, I realized it's utter garbage. The pool would
swap up and down, not right and left. Never mind.
--
Jim Gillogly
2 Afterlithe S.R. 1999, 19:44

Renegade

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Jun 25, 1999, 3:00:00 AM6/25/99
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> I use Perl for one-off programs and things that aren't computationally
> intensive -- analyzing and diagnosing unknowns, for example. C is
> better for the serious crunching,

Perl? C? Stop the horror. Real cryppies code in IMP! Next you be telling
us it ran on a Wintel box......

:-)

-Mike

Jim Gillogly

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Jun 25, 1999, 3:00:00 AM6/25/99
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I'm not that depraved -- Linux, of course.

--
Jim Gillogly
2 Afterlithe S.R. 1999, 21:28

Douglas A. Gwyn

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Jun 26, 1999, 3:00:00 AM6/26/99
to
Jim Gillogly wrote:
> Is there another pool on the concave side of the cipher panels?

Not that I recall.

However, there are other pieces of the complete work scattered
around the courtyard: rocks, engravings, a stream, etc. Among
them is a lodestone, for its symbolism.

You can get a good look at the main message-bearing part of the
sculpture on a tape of the Today Show (7:16-7:21 EDT, Friday
25-Jun-1999). Some additional information can be found in the
book "Inside the CIA" by Clifton Berry Jr., but its Kryptos
photos are just the two we've all seen elsewhere.

Douglas A. Gwyn

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Jun 26, 1999, 3:00:00 AM6/26/99
to
Jim Gillogly wrote:
> Reflecting on this, I realized it's utter garbage. The pool would
> swap up and down, not right and left. Never mind.

Um, Jim, mirrors don't reverse in any particular direction.
Martin Gardner had a discussion of this in one of his books:
Why is your image in a flat mirror reversed left-to-right,
not top-to-bottom? (Think about it; it can produce one of
those moments of "enlightenment".)

B & J

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Jun 26, 1999, 3:00:00 AM6/26/99
to

I got quite interested in this KRYPTOS code thing, and was able to find the
keys for the first
2 parts, but does anyone know if the keys mean anything at all , perhaps
encrypted ? seems like gibberish to me....

- Ben

wtshaw

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Jun 26, 1999, 3:00:00 AM6/26/99
to
In article <37744D9B...@null.net>, "Douglas A. Gwyn"
<DAG...@null.net> wrote:

Congratulations Jim...now, time for recovery. If you come to Atlanta for
the convention, please bring your costume; pardon me if I leave my best
suit, my coveralls, at home.

Something a mirror cannot fully reverse:

.emoh ta ,sllarevoc ym ,tius tseb ym evael I fi em nodrap ;emutsoc ruoy
gnirb esaelp ,noitnevnoc eht rof atnaltA ot emoc uoy fI .yrevocer rof emit
,won...miJ snoitalutargnoC
--
It's always possible that a politician is acting out of principles.
--Michael Kinsley of Slate.com

Jim Gillogly

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Jun 26, 1999, 3:00:00 AM6/26/99
to

Yes -- if you set it up like a matrix, with the KRYPTOSABC...
keyword across the top as the plaintext alphabet, and each
offset KRYPTOSABC... keyword underneath it at the right offset
so that the 1st ciphertext letter is below the corresponding
plaintext letter in the top alphabet, you will be able to read
whichever keyword you recovered in a vertical line somewhere
in the matrix.

Look under the K to find the keyword Jim Sanborn used when he
encrypted the section. Each is an English word.

--
Jim Gillogly
Trewesday, 3 Afterlithe S.R. 1999, 22:28
12.19.6.5.11, 2 Chuen 19 Zotz, Third Lord of Night

Lincoln Yeoh

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Jun 27, 1999, 3:00:00 AM6/27/99
to
On Sat, 26 Jun 1999 03:49:50 GMT, "Douglas A. Gwyn" <DAG...@null.net>
wrote:

>Um, Jim, mirrors don't reverse in any particular direction.


>Martin Gardner had a discussion of this in one of his books:
>Why is your image in a flat mirror reversed left-to-right,
>not top-to-bottom?

Maybe it because your right hand looks like your left hand and your head
doesn't look like your feet?

They just mirror stuff, that's all, just like shadows in some ways.

Lincoln Yeoh

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Jun 27, 1999, 3:00:00 AM6/27/99
to
On Thu, 24 Jun 1999 11:31:12 -0700, Jim Gillogly <j...@acm.org> wrote:
>Today Show looked rather like me. I acknowledged the resemblance, but
>pointed out that it had more hair on top than I do, and she was forced to
>recant.

Hmm. So you've been gaining face along with experience? ;).

I dunno when it'll be my turn. But a friend told me it's ok, it's just he
has problems washing his face - doesn't know where to stop. :)

wtshaw

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Jun 27, 1999, 3:00:00 AM6/27/99
to
In article <377622dd...@nntp.jaring.my>, ly...@pop.jaring.nospam.my wrote:
>
> Maybe it because your right hand looks like your left hand and your head
> doesn't look like your feet?
>
> They just mirror stuff, that's all, just like shadows in some ways.
>
According to Alice, mirrors can be best used by walking through them, but
everytime I try, the guy on the other side seems not to like the idea
'cause he hits back.

Nicol So

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Jun 28, 1999, 3:00:00 AM6/28/99
to
Lincoln Yeoh wrote:
>
> On Sat, 26 Jun 1999 03:49:50 GMT, "Douglas A. Gwyn" <DAG...@null.net>
> wrote:
>
> >Um, Jim, mirrors don't reverse in any particular direction.
> >Martin Gardner had a discussion of this in one of his books:
> >Why is your image in a flat mirror reversed left-to-right,
> >not top-to-bottom?
>
> Maybe it because your right hand looks like your left hand and your head
> doesn't look like your feet?
>
> They just mirror stuff, that's all, just like shadows in some ways.

It's deeper than that. Without spoiling the fun, I can tell you that
it's not an optics problem. It's not even a physics problem--it's a
philosophical one.

Consider this thought experiment: you stand in front of a mirror and
take a portrait of yourself with a Polaroid camera. The picture
basically captures what you see in the mirror. Then a friend of yours
moves into the position where the mirror was, and takes another picture
of you with another Polaroid camera.

Now compare the two pictures, they are (basically) inverted images of
each other *along the vertical axis*. Why does the inversion take place
along one of infinitely many possible axes? Einstein said there's no
preferred frame of reference in nature. Why does the inversion
"phenomenon" take place along a particular axis but not others?

Answering these questions is the real point of the puzzle.

Have fun.
Nicol

Ed Yang

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Jun 28, 1999, 3:00:00 AM6/28/99
to
Mirrors do not invert. What happens is a person turns around
a vertical axis to look at the real face, causing the person
to misinterpret the reflection. If you turn on a horizontal
axis, turning upside down, the mirror image would cause one
to misinterpret the mirror image as inverting up-to-down.

--
Oxygen : Love It Or Leave It !

Jim Gillogly

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Jun 28, 1999, 3:00:00 AM6/28/99
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Douglas A. Gwyn wrote:
> Back to the original thing about reflecting the wrong side of
> Kryptos in a pool: Yes, it makes the letters appear normal.

Not quite normal -- they'll appear upside down. Note that on
the wrong side the rows start from the right, and they'll still
be on the right in the reflection. If you freeze the pond and
stand it up behind you and turn around and look at it, the letters
will look normal. Mirrors are trickier than they look.

However, I read some specs from Sanborn, and it turns out the
pool is supposed to be agitated, which would presumably make it
difficult to extract a coherent reflection from the sculpture.
Sounds symbolic of decryption, somehow...

--
Jim Gillogly
Highday, 6 Afterlithe S.R. 1999, 06:30
12.19.6.5.14, 5 Ix 2 Tzec, Sixth Lord of Night

S.T.L.

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Jun 29, 1999, 3:00:00 AM6/29/99
to
<<It's not even a physics problem--it's a
philosophical one.>>

It's not even a philosophical (gag) problem. It's NOT a problem!

Mirrors invert FRONT-TO-BACK. When we imagine ourselves standing side-by-side
our mirror image, making our Fronts identical, then another direction MUST be
reversed. We like to think that L-R is reversed because we are bilaterally
symmetric. This is, because as someone else said, our left side resembles our
right side much more than our head resembles our feet. If, however, we were
simply C F Cl Br I atoms (if those exist), then we would have no problem - we
would understand the concept of chirality and not be confused by the front-back
switch.

Have fun and avoid philosophy at all costs.

-*---*-------
S.T.L. ===> STL...@aol.com <=== BLOCK RELEASED! 2^3021377 - 1 is PRIME!
Quotations: http://quote.cjb.net Main website: http://137.tsx.org MOO!
"Xihribz! Peymwsiz xihribz! Qssetv cse bqy qiftrz!" e^(i*Pi)+1=0 F00FC7C8
E-mail block is gone. It will return if I'm bombed again. I don't care, it's
an easy fix. Address is correct as is. The courtesy of giving correct E-mail
addresses makes up for having to delete junk which gets through anyway. Join
the Great Internet Mersenne Prime Search at http://entropia.com/ips/ Now my
.sig is shorter and contains 3379 bits of entropy up to the next line's end:
-*---*-------

Card-holding member of the Dark Legion of Cantorians, the Great SRian
Conspiracy, the Triple-Sigma Club, the Union of Quantum Mechanics, the
Holy Order of the Catenary, and People for Ethical Treatment of Digital
Tierran Organisms
Avid watcher of "World's Most Terrifying Causality Violations", "World's
Scariest Warp Accidents", "When Tidal Forces Attack: Caught on Tape",
and "When Kaons Decay: World's Most Amazing CP Symmetry Breaking Caught
On [Magnetic] Tape"
Patiently awaiting the launch of Gravity Probe B and the discovery of M39
Physics Commandment #4: Thou Shalt Have Quantized Angular Momenta.

Douglas A. Gwyn

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Jun 29, 1999, 3:00:00 AM6/29/99
to
"S.T.L." wrote:
> Mirrors invert FRONT-TO-BACK. When we imagine ourselves standing side-by-side
> our mirror image, making our Fronts identical, then another direction MUST be
> reversed. We like to think that L-R is reversed because we are bilaterally
> symmetric. This is, because as someone else said, our left side resembles our
> right side much more than our head resembles our feet. If, however, we were
> simply C F Cl Br I atoms (if those exist), then we would have no problem - we
> would understand the concept of chirality and not be confused by the front-back
> switch.

The trick is that, to compare the object and its image, we map one
onto the other. For almost everyone, that mapping consists of
treating the image as a real image (rather than virtual) and
rotating the object *about a vertical axis*, then translating it
onto the (real) image for comparison. The left-to-right reversal
is a property of the specific mapping (rotation) we use.

Douglas A. Gwyn

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Jun 29, 1999, 3:00:00 AM6/29/99
to
Ed Yang wrote:
> Mirrors do not invert. What happens is a person turns around
> a vertical axis to look at the real face, causing the person
> to misinterpret the reflection. If you turn on a horizontal
> axis, turning upside down, the mirror image would cause one
> to misinterpret the mirror image as inverting up-to-down.

And if you change the mapping to rotation about a 45-degree
axis, mirrors appear to rotate objects by 90 degrees as well
as changing their "handedness".

Douglas A. Gwyn

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Jun 29, 1999, 3:00:00 AM6/29/99
to
Jim Gillogly wrote:
> Not quite normal -- they'll appear upside down.

Depends on how you look at it.

Nicol So

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Jun 29, 1999, 3:00:00 AM6/29/99
to
S.T.L. wrote:
>
> <<It's not even a physics problem--it's a
> philosophical one.>>
>
> It's not even a philosophical (gag) problem. It's NOT a problem!

The philosophical part of the puzzle is one's conception of what he
should look like when his image is normal and uninverted. In most
people's conception, this involves a (real or imaginary) observation
performed from a certain position and with a certain (preferred)
orientation.

> Mirrors invert FRONT-TO-BACK.

This is true.

> We like to think that L-R is reversed because we are bilaterally
> symmetric. This is, because as someone else said, our left side resembles our
> right side much more than our head resembles our feet.

This is not true. In the thought experiment in my previous message, the
person would observe the same apparent inversion even if he's obviously
not bilaterally symmetric (say, because of some costumes he's wearing).
There's a reason why I introduced the Polaroid pictures into the
experiment--the lateral inversion can be detected even with a machine,
and has nothing to do with the bilateral symmetry we've come to expect
of our images.

> If, however, we were
> simply C F Cl Br I atoms (if those exist), then we would have no problem - we
> would understand the concept of chirality and not be confused by the front-back
> switch.
>

> Have fun and avoid philosophy at all costs.

Philosophy can be fun too!

Nicol

S.T.L.

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Jun 29, 1999, 3:00:00 AM6/29/99
to
<<and has nothing to do with the bilateral symmetry we've come to expect
of our images.>>

That's because you still insist on rotating yourself _around the side to_ "map"
yourself next to your mirror image. You think (as I do) in bilaterally
symmetric ways. A creature with a bilateral symmetry that runs from the ground
up, but at a 45-degree angle, will probably map himself next to his mirror
image in such a way that he sees the mirror do even weirder stuff (rotations
and such). A spherical creature with 4 differently colored dots on it will have
no reason to choose any particular way to map itself to its mirror image and
will actually recognize that front-back is truly being inverted. Unlike a
human, which seems to have a hell of a time recognizing this.

As you say:


<<In most
people's conception, this involves a (real or imaginary) observation
performed from a certain position and with a certain (preferred)
orientation.>>

The certain preferred orientation that YOU are using is simply thus: you and
your mirror image (in this imaginary observation) have both your feet on the
same floor and have your front-sides in the same direction. Therefore
left-right is inverted.

<<if he's obviously
not bilaterally symmetric (say, because of some costumes he's wearing). >>

G'uh. He has been bilaterally symmetric all his life and therefore choose to
map himself next to his mirror image in such a way that L-R is *still* reversed
because it seems more "natural" than having up and down reversed.

<<and has nothing to do with the bilateral symmetry we've come to expect
of our images.>>

Of course not. It has everything to do with the mapping process.

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Card-holding member of the Dark Legion of Cantorians, the Great SRian
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Avid watcher of "World's Most Terrifying Causality Violations", "World's
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Patiently awaiting the launch of Gravity Probe B and the discovery of M39

Physics Commandment #5: Thou Shalt Not Remain At Rest Inside An Ergosphere.

John Savard

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Jun 29, 1999, 3:00:00 AM6/29/99
to
Nicol So <nob...@no.spam.please> wrote, in part:

>Lincoln Yeoh wrote:
>> On Sat, 26 Jun 1999 03:49:50 GMT, "Douglas A. Gwyn" <DAG...@null.net>
>> wrote:

>> >Um, Jim, mirrors don't reverse in any particular direction.
>> >Martin Gardner had a discussion of this in one of his books:
>> >Why is your image in a flat mirror reversed left-to-right,
>> >not top-to-bottom?

>> Maybe it because your right hand looks like your left hand and your head
>> doesn't look like your feet?

>> They just mirror stuff, that's all, just like shadows in some ways.

>It's deeper than that. Without spoiling the fun, I can tell you that

>it's not an optics problem. It's not even a physics problem--it's a
>philosophical one.

>Consider this thought experiment: you stand in front of a mirror and


>take a portrait of yourself with a Polaroid camera. The picture
>basically captures what you see in the mirror. Then a friend of yours
>moves into the position where the mirror was, and takes another picture
>of you with another Polaroid camera.

>Now compare the two pictures, they are (basically) inverted images of
>each other *along the vertical axis*. Why does the inversion take place
>along one of infinitely many possible axes? Einstein said there's no
>preferred frame of reference in nature. Why does the inversion
>"phenomenon" take place along a particular axis but not others?

Since the fun has already been spoiled...

Between taking the two pictures, the Polaroid camera was rotated so
that its up-down axis remained invariant. Someone could have taken a
picture of you, and then could have done a backflip to photograph your
mirror image.

Let the mirror be at the end of a hallway leading north.

You face the mirror.

Your mirror image faces south. This makes sense, because the mirror
faces south, and so the direction _perpendicular_ to the mirror is
special.

Your right hand, which is on your east side, is also on the east side
of your mirror image...

just as your head, which is on top of you, is on the top of your
mirror image.

So, considering you and your mirror image in absolute coordinates,
neither up and down nor east and west are reversed: north and south
are reversed, which are special, because that axis is the one
perpendicular to the mirror, the other two being parallel to its
surface.

Normally, though, you don't talk about your "east" hand or your "west"
hand. Instead, you talk about your right hand and your left hand.
Right and left aren't absolute directions, the way up and down (or
east and west) are; instead, they are relative directions. They're
defined in terms of up and down and front and back (look at an object
from its front - hence, you are looking in its relative "back"
direction: right is 90 degrees counterclockwise from up, left is 90
degrees clockwise from up).

So, when you are facing the mirror, what happens makes sense: up and
down stay the same, but since north and south, corresponding to front
and back, are reversed in your image, the relative direction "right",
for your image, points to the image of your _left_ hand.

Suppose you weren't facing the mirror, but looking sideways. Then
right and left would be reversed in a "real" sense, but that wouldn't
make a difference: one still sees right and left as reversed, because
one maps oneself on to one's image by performing a rotation with a
constant vertical axis. Because that's a kind of motion people do in
real life more often than, say, backflips.

full...@aspi.net

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Jun 29, 1999, 3:00:00 AM6/29/99
to
Douglas A. Gwyn wrote:
>
> "S.T.L." wrote:
> > Mirrors invert FRONT-TO-BACK. When we imagine ourselves standing side-by-side
> > our mirror image, making our Fronts identical, then another direction MUST be
> > reversed. We like to think that L-R is reversed because we are bilaterally

> > symmetric. This is, because as someone else said, our left side resembles our
> > right side much more than our head resembles our feet. If, however, we were

> > simply C F Cl Br I atoms (if those exist), then we would have no problem - we
> > would understand the concept of chirality and not be confused by the front-back
> > switch.
>
> The trick is that, to compare the object and its image, we map one
> onto the other. For almost everyone, that mapping consists of
> treating the image as a real image (rather than virtual) and
> rotating the object *about a vertical axis*, then translating it
> onto the (real) image for comparison. The left-to-right reversal
> is a property of the specific mapping (rotation) we use.

The mapping is controlled by the frame of reference. Since the normal
one is not inertial, the vertical axis is special. In one word the
reason is "gravity".

Douglas A. Gwyn

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Jun 29, 1999, 3:00:00 AM6/29/99
to
full...@aspi.net wrote:
> The mapping is controlled by the frame of reference. Since the normal
> one is not inertial, the vertical axis is special. In one word the
> reason is "gravity".

That's why we think most easily of rotating ourselves around the
vertical axis for comparison purposes, but it isn't a "frame of
reference" issue in the relativistic sense.

Douglas A. Gwyn

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Jun 29, 1999, 3:00:00 AM6/29/99
to
"S.T.L." wrote:
> The certain preferred orientation that YOU are using is simply thus:
> you and your mirror image (in this imaginary observation) have both

> your feet on the same floor and have your front-sides in the same
> direction. Therefore left-right is inverted.

That begs the question. You both have your right hand on the same
wall (perhaps), too.

wtshaw

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Jun 29, 1999, 3:00:00 AM6/29/99
to
In article <3778f3c0...@news.prosurfr.com>,

jsa...@tenMAPSONeerf.edmonton.ab.ca (John Savard) wrote:
>
> >Consider this thought experiment: you stand in front of a mirror and
> >take a portrait of yourself with a Polaroid camera. The picture
> >basically captures what you see in the mirror. Then a friend of yours
> >moves into the position where the mirror was, and takes another picture
> >of you with another Polaroid camera.
>
Just have your friend take your picture in front of the inscription with a
throw-away camera. Then, take the film to Walmart; from my experience,
you have a fair chance that the picture will be printed backwards by some
zealous technician correcting an *obvious* problem, or by one who is not
paying attention enough to print the usual correct side in the first
place.

David Wagner

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Jun 29, 1999, 3:00:00 AM6/29/99
to
In article <37721262...@acm.org>, Jim Gillogly <j...@acm.org> wrote:
> Each of the systems so far would be solvable by most ACA members
> with sufficient time, if armed with the knowledge that it was in
> fact solvable. A positive mental attitude is a real key to this
> kind of thing.

No kidding!

I can agree, from personal experience. The first time I looked at
CMEA (a cellphone cipher), I just assumed it was probably going to be
too tough a nut to crack. When I heard through the grapevine that
someone else had broken it, but wasn't allowed to publish, I was
motivated to look again -- and I found an attack in just 48 hours.

It's amazing how much of a difference it makes. I almost wish
someone reputable would lie to the world and claim such-and-such
a cipher can be broken, just to see what the results are. :-)

Douglas A. Gwyn

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Jun 30, 1999, 3:00:00 AM6/30/99