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Science Forum Index » Cryptography Forum » One time pad...
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| jmorton123... |
Posted: Mon Jul 21, 2008 1:36 am |
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I was doing some searching and came across some software but it
doesn't seem to be available any longer.
It's called Original Absolute Privacy.
Does anyone have a copy or know how I can get a copy?
The website is not up.
Thanks.
jmorton123 at (no spam) rock dot com |
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| jmorton123... |
Posted: Mon Jul 21, 2008 5:55 am |
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On Jul 21, 7:18 am, rossum <rossu... at (no spam) coldmail.com> wrote:
Quote: On Mon, 21 Jul 2008 04:36:52 -0700 (PDT), jmorton123
jmorton... at (no spam) rock.com> wrote:
I was doing some searching and came across some software but it
doesn't seem to be available any longer.
It's called Original Absolute Privacy.
Does anyone have a copy or know how I can get a copy?
The website is not up.
Thanks.
jmorton123 at (no spam) rock dot com
I was able to find "AbsolutePrivacy" (http://www.cryptobase.com/) but
that does not use a One Time Pad. Software for the OTP is trivial,
the big problem is with key distribution.
What did the software you were looking for do? There may well be an
alternative.
rossum
I found plenty of references to an OAP-L3 encryption software in this
newsgroup from around 1999.
Seems to have generated a lot of controversy.
Thought I'd like to check it out.
On the off chance someone from back then was still participating in
this newsgroup and actually bothered to download it and save it. I
guess it would have to be a rather serious crypto guy to not only
download it but archive it, too.
But I thought it'd be worth a try.
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream. It seems that there are 10! ways to
arrange these ten digits. Anyway, without the software or the website
I don't have much of a clue how the random numbers were generated.
This is all I'm interested in is the pseudo random number generator.
From there anyone can write encryption software.
Thanks.
JM |
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| Phil Carmody... |
Posted: Mon Jul 21, 2008 7:17 am |
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jmorton123 <jmorton123 at (no spam) rock.com> writes:
Quote: I was doing some searching and came across some software but it
doesn't seem to be available any longer.
It's called Original Absolute Privacy.
OAP? Sounds a bit old.
Quote: Does anyone have a copy or know how I can get a copy?
Doug Gwyn, amongst others, has posted the full source
code to an OTP program on this group already. Use your
prefered usenet archive to find it.
Quote: The website is not up.
Good.
Phil
--
Dear aunt, let's set so double the killer delete select all.
-- Microsoft voice recognition live demonstration |
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| rossum... |
Posted: Mon Jul 21, 2008 9:18 am |
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Guest
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On Mon, 21 Jul 2008 04:36:52 -0700 (PDT), jmorton123
<jmorton123 at (no spam) rock.com> wrote:
Quote: I was doing some searching and came across some software but it
doesn't seem to be available any longer.
It's called Original Absolute Privacy.
Does anyone have a copy or know how I can get a copy?
The website is not up.
Thanks.
jmorton123 at (no spam) rock dot com
I was able to find "AbsolutePrivacy" (http://www.cryptobase.com/) but
that does not use a One Time Pad. Software for the OTP is trivial,
the big problem is with key distribution.
What did the software you were looking for do? There may well be an
alternative.
rossum |
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| rossum... |
Posted: Mon Jul 21, 2008 1:33 pm |
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On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
<jmorton123 at (no spam) rock.com> wrote:
Quote: The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP. The security
proof of an OTP requires a genuinely random key used only once. A
pseudo-random key does not meet the criteria and so is not provably
secure.
An OTP with a pseudo random keystream is called a stream cypher, and
may or may not be secure. The fact that whoever wrote this program
calls a stream cypher an OTP indicates that they are not well enough
aquainted with the basics of cryptography. The use of digits rather
than bytes or larger tends to reinforce this indication.
Quote: It seems that there are 10! ways to arrange these ten digits.
A lot will depend on the detail of how one of the many permutations of
the digits is selected. If the attacker can easily reproduce the
selection then the cypher is broken.
Quote: Anyway, without the software or the website
I don't have much of a clue how the random numbers were generated.
Indeed, that is the crucial part of any stream cypher, how the
keystream is generated.
There are a number of cryptographic quality PRNGs avilable: Blum,
Blum, Shub (BBS), Yarrow and Fortuna are all described on the web. As
for stream cyphers, RC4 is very easy to program as a learning
exercise, but is broken. Salsa-20, Rabbit-128 and Phelix are more
modern but not so easy to code.
rossum
Quote: This is all I'm interested in is the pseudo random number generator.
From there anyone can write encryption software. |
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| Phil Carmody... |
Posted: Mon Jul 21, 2008 4:59 pm |
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rossum <rossum48 at (no spam) coldmail.com> writes:
Quote: On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
jmorton123 at (no spam) rock.com> wrote:
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP.
With loons around, it's best to simply avoid using the letters
'O', 'T', and 'P' in that order in the context of things that
are not OTPs.
Phil
--
Dear aunt, let's set so double the killer delete select all.
-- Microsoft voice recognition live demonstration |
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| Ertugrul Söylemez... |
Posted: Mon Jul 21, 2008 7:42 pm |
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rossum <rossum48 at (no spam) coldmail.com> wrote:
Quote: On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
jmorton123 at (no spam) rock.com> wrote:
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP. The security
proof of an OTP requires a genuinely random key used only once. A
pseudo-random key does not meet the criteria and so is not provably
secure.
I'd like to add that the OTP gives you perfect secrecy. This is nowhere
near perfect or even provable security. You get perfect security for a
cryptosystem, when it cannot be broken, unless the keys are known. The
OTP does not fulfill this requirement, because two messages encrypted
with the same key will turn it into a mere Vigenere cipher, enabling
easy classical cryptanalysis.
Greets,
Ertugrul.
--
nightmare = unsafePerformIO (getWrongWife >>= sex) |
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| Unruh... |
Posted: Tue Jul 22, 2008 1:29 am |
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rossum <rossum48 at (no spam) coldmail.com> writes:
Quote: On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
jmorton123 at (no spam) rock.com> wrote:
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP. The security
proof of an OTP requires a genuinely random key used only once. A
pseudo-random key does not meet the criteria and so is not provably
secure.
An OTP with a pseudo random keystream is called a stream cypher, and
may or may not be secure. The fact that whoever wrote this program
calls a stream cypher an OTP indicates that they are not well enough
aquainted with the basics of cryptography. The use of digits rather
than bytes or larger tends to reinforce this indication.
It seems that there are 10! ways to arrange these ten digits.
A lot will depend on the detail of how one of the many permutations of
the digits is selected. If the attacker can easily reproduce the
selection then the cypher is broken.
Anyway, without the software or the website
I don't have much of a clue how the random numbers were generated.
Indeed, that is the crucial part of any stream cypher, how the
keystream is generated.
There are a number of cryptographic quality PRNGs avilable: Blum,
Blum, Shub (BBS), Yarrow and Fortuna are all described on the web. As
for stream cyphers, RC4 is very easy to program as a learning
exercise, but is broken. Salsa-20, Rabbit-128 and Phelix are more
Isn't "broken" a bit harsh. Is it anything but a slight bias in the long
term statistics of the output? Ie, if I give you a 1MB file encrytped by
RC4, and give you the first 1K of plaintext, can you recover the rest of
the plaintext?
Quote: modern but not so easy to code.
rossum
This is all I'm interested in is the pseudo random number generator.
From there anyone can write encryption software. |
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| Phil Carmody... |
Posted: Tue Jul 22, 2008 4:00 am |
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Ertugrul Söylemez <es at (no spam) ertes.de> writes:
Quote: rossum <rossum48 at (no spam) coldmail.com> wrote:
On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
jmorton123 at (no spam) rock.com> wrote:
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP. The security
proof of an OTP requires a genuinely random key used only once. A
pseudo-random key does not meet the criteria and so is not provably
secure.
I'd like to add that the OTP gives you perfect secrecy. This is nowhere
near perfect or even provable security. You get perfect security for a
cryptosystem, when it cannot be broken, unless the keys are known. The
OTP does not fulfill this requirement, because two messages encrypted
with the same key will turn it into a mere Vigenere cipher, enabling
easy classical cryptanalysis.
You cannot, by definition, encrypt two messages with the same key
in an OTP system, as it's not a OTP if you're doing that.
There's more to the system than just the primitive (add one
word of key to one word of plaintext in an appropriate group
to get one word of cyphertext).
Phil
--
Dear aunt, let's set so double the killer delete select all.
-- Microsoft voice recognition live demonstration |
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| Simon Johnson... |
Posted: Tue Jul 22, 2008 7:19 am |
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Guest
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Quote: Isn't "broken" a bit harsh. Is it anything but a slight bias in the long
term statistics of the output? Ie, if I give you a 1MB file encrytped by
RC4, and give you the first 1K of plaintext, can you recover the rest of
the plaintext?
Yes, this has been debated to death over the years.
Over tens of gigabytes, the bias in RC4 is probably sufficient to tell
the difference between English and say Chinese if the plain-text was
encoded in Unicode.
No self respecting cipher has that fault; That, to me, is a break.
Simon. |
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| ... |
Posted: Tue Jul 22, 2008 3:40 pm |
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On Jul 22, 6:15 pm, Ertugrul Söylemez <e... at (no spam) ertes.de> wrote:
Quote: Simon Johnson <simon.john... at (no spam) gmail.com> wrote:
Isn't "broken" a bit harsh. Is it anything but a slight bias in the
long term statistics of the output? Ie, if I give you a 1MB file
encrytped by RC4, and give you the first 1K of plaintext, can you
recover the rest of the plaintext?
Yes, this has been debated to death over the years.
Over tens of gigabytes, the bias in RC4 is probably sufficient to tell
the difference between English and say Chinese if the plain-text was
encoded in Unicode.
No self respecting cipher has that fault; That, to me, is a break.
I really don't think that ciphers have feelings. They have a purpose
and the purpose of RC4 is quite limited, but for its purpose it performs
very well. It is harsh to call RC4 in the context of WPA broken,
because it isn't. It's extremely fast and secure for usage in home
WLANs, even at a massive scale.
Greets,
Ertugrul.
--
nightmare = unsafePerformIO (getWrongWife >>= sex)
I have to agree with Ertugrul (not that anyone is swayed by my
assessment) that Simon Johnson's response to Unruh seems harsh and add
that his example of "Over tens of gigabytes, the bias in RC4 is
probably sufficient to tell the difference between English and say
Chinese if the plain-text was encoded in Unicode." needs to be
explained with more than jingoistic sloganeering, if Simon would be so
kind.
We're all aware of the bias that occurs around one gigabyte that will
identify the underlying algorithm as RC4.
Simon's example is quoting single data sets of at least 20 gigabytes
without re-keying and is suggesting that it is possible to distinguish
(at least) the following difference in plaintext of Unicode:
00h xxh 00h xxh 00h xxh 00h xxh... 00h xxh
xxh xxh xxh xxh xxh xxh xxh xxh... xxh xxh
were xx is a value between 00h and FFh, and further with enough
resolution to distinguish Chinese (or Japanese or Korean?) text which
seems like someone needs to hear the phrase "Slow down speed racer..." |
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| Ertugrul Söylemez... |
Posted: Tue Jul 22, 2008 8:10 pm |
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Phil Carmody <thefatphil_demunged at (no spam) yahoo.co.uk> wrote:
Quote: Ertugrul Söylemez <es at (no spam) ertes.de> writes:
rossum <rossum48 at (no spam) coldmail.com> wrote:
A pseudo random stream can only give you a pseudo OTP. The
security proof of an OTP requires a genuinely random key used only
once. A pseudo-random key does not meet the criteria and so is not
provably secure.
I'd like to add that the OTP gives you perfect secrecy. This is
nowhere near perfect or even provable security. You get perfect
security for a cryptosystem, when it cannot be broken, unless the
keys are known. The OTP does not fulfill this requirement, because
two messages encrypted with the same key will turn it into a mere
Vigenere cipher, enabling easy classical cryptanalysis.
You cannot, by definition, encrypt two messages with the same key in
an OTP system, as it's not a OTP if you're doing that.
You know that programmers' view of definitions isn't always what it
should be. And more yet, as you say, there is more to a system than its
primitive, which confirms my statement. The primitive gives the perfect
secrecy, and now the system is supposed to give decent security.
There is no OTP-based system, which gives "perfect" security.
Especially in its raw form, the OTP wouldn't even protect a money
transfer from being tampered with.
Greets,
Ertugrul.
--
nightmare = unsafePerformIO (getWrongWife >>= sex) |
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| Ertugrul Söylemez... |
Posted: Tue Jul 22, 2008 8:15 pm |
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Guest
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Simon Johnson <simon.johnson at (no spam) gmail.com> wrote:
Quote: Isn't "broken" a bit harsh. Is it anything but a slight bias in the
long term statistics of the output? Ie, if I give you a 1MB file
encrytped by RC4, and give you the first 1K of plaintext, can you
recover the rest of the plaintext?
Yes, this has been debated to death over the years.
Over tens of gigabytes, the bias in RC4 is probably sufficient to tell
the difference between English and say Chinese if the plain-text was
encoded in Unicode.
No self respecting cipher has that fault; That, to me, is a break.
I really don't think that ciphers have feelings. They have a purpose
and the purpose of RC4 is quite limited, but for its purpose it performs
very well. It is harsh to call RC4 in the context of WPA broken,
because it isn't. It's extremely fast and secure for usage in home
WLANs, even at a massive scale.
Greets,
Ertugrul.
--
nightmare = unsafePerformIO (getWrongWife >>= sex) |
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| rossum... |
Posted: Wed Jul 23, 2008 5:57 am |
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Guest
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On Tue, 22 Jul 2008 06:29:27 GMT, Unruh <unruh-spam at (no spam) physics.ubc.ca>
wrote:
Quote: rossum <rossum48 at (no spam) coldmail.com> writes:
On Mon, 21 Jul 2008 08:55:03 -0700 (PDT), jmorton123
jmorton123 at (no spam) rock.com> wrote:
The software is based on using ten digit arrays of the digits 0-9 to
generate a pseudo random stream.
A pseudo random stream can only give you a pseudo OTP. The security
proof of an OTP requires a genuinely random key used only once. A
pseudo-random key does not meet the criteria and so is not provably
secure.
An OTP with a pseudo random keystream is called a stream cypher, and
may or may not be secure. The fact that whoever wrote this program
calls a stream cypher an OTP indicates that they are not well enough
aquainted with the basics of cryptography. The use of digits rather
than bytes or larger tends to reinforce this indication.
It seems that there are 10! ways to arrange these ten digits.
A lot will depend on the detail of how one of the many permutations of
the digits is selected. If the attacker can easily reproduce the
selection then the cypher is broken.
Anyway, without the software or the website
I don't have much of a clue how the random numbers were generated.
Indeed, that is the crucial part of any stream cypher, how the
keystream is generated.
There are a number of cryptographic quality PRNGs avilable: Blum,
Blum, Shub (BBS), Yarrow and Fortuna are all described on the web. As
for stream cyphers, RC4 is very easy to program as a learning
exercise, but is broken. Salsa-20, Rabbit-128 and Phelix are more
Isn't "broken" a bit harsh.
Probably, "obsolescent" might have been better. I wanted to indicate
to the OP that it would be better not to incorporate RC4 into a new
system.
rossum
Quote: Is it anything but a slight bias in the long
term statistics of the output? Ie, if I give you a 1MB file encrytped by
RC4, and give you the first 1K of plaintext, can you recover the rest of
the plaintext?
modern but not so easy to code.
rossum
This is all I'm interested in is the pseudo random number generator.
From there anyone can write encryption software. |
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| Simon Johnson... |
Posted: Wed Jul 23, 2008 6:50 am |
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Guest
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Quote: I really don't think that ciphers have feelings. They have a purpose
and the purpose of RC4 is quite limited, but for its purpose it performs
very well. It is harsh to call RC4 in the context of WPA broken,
because it isn't. It's extremely fast and secure for usage in home
WLANs, even at a massive scale.
It's all a question of personal opinion really. There are use-cases
where using RC4 could leak information that would not be leaked as a
result of using AES.
I do feel as if RC4 gets a free pass sometimes. I'm not sure why,
although I have a suspicion that it's because Rivest invented it.
I feel that if I invented a cipher with such a bad bias it would
(rightly) be dismissed as useless.
Why products continue to use RC4 when so many AES implementations
exist is baffling. RC4 was invented in 1987. The world has moved on
from then. Attacks have moved on from then.
There is no good reason to use this cipher in 2008.
Simon. |
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