Big Bill wrote:

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A recurring thought has been keeping me awake of late and that is
whether someone without your private key and without your passphrase
can decrypt a message encrypted with your public key. Often, the
argument revolves around applying greater and greater computer power
to the task as key lengths become longer and longer.

But it seems to me that there is an ultimate limit to the power of
computers beyond which no technological breakthrough can reach.

Bear with me whilst I explain.If we reduce the size of a byte of
memory to an atom of oxygen (which has eight electrons, one for each
bit in the byte), it still takes a non-zero amount of time to flip
the spin-state of each electron. This defines the ultimate speed of
both a memory chip and a processor. Note that it takes the same
amount of time to flip the spin-state of the one electron in an atom
of hydrogen, so we don't gain anything by changing atoms.

If we pack the atoms of our megacomputer as dense as possible
without creating a neutron star, there is still a non-zero distance
between atoms. It takes a finite amount of time for a signal to
travel that distance. That defines the overall speed of the
computer.

If we take all the atoms in the universe (oxygen, hydrogen, and all
the others), that defines the ultimate size of a computer. We can
allocate the atoms between memory and processor. Just remember,
the number of atoms is finite; and we must reserve some for the
nuclear power plant that will run this infernal device. Thus, the
memory of our megacomputer is limited.

I saw this concept in some very old technical periodical where the
capacity and speed of an ultimate computer were quantified. The
article was published just before the dawn of PCs, when minicomputers
and microcomputers were being installed with faster capabilities at
far less cost than mainframes. The point is that we can conceive of
finite problems to be solved on a computer that exceed the capacity
of any computer that could ever exist.

As there is indeed a limit to computer power before conjecturing
about a future super-computer cracking a PGP-encrypted message,
we should consider whether that computer could fit into the universe.

Your thoughts on this would be very welcome. I have run out avenues
to explore and worse still my GP will not increase my dose of
Nembies.


You are talking about brute force attacks.

In fact, your message is not random, and there are only a fw things you
probably wrte about, so anyine who really wants t crack it probably
could have some idea of how to do it.

A lot of intelleigence can be gleaned by mointoring traffic density and
source/destination. Even if you can't read it.

Finally, if the CIA want to read your messages, they would probably
break seamlessly into your house and download your encryptions software
onto their own machines. :-)


Dave

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Big Bill wrote:

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Hash: SHA1

A recurring thought has been keeping me awake of late and that is
whether someone without your private key and without your passphrase
can decrypt a message encrypted with your public key. Often, the
argument revolves around applying greater and greater computer power
to the task as key lengths become longer and longer.

But it seems to me that there is an ultimate limit to the power of
computers beyond which no technological breakthrough can reach.

Bear with me whilst I explain.If we reduce the size of a byte of
memory to an atom of oxygen (which has eight electrons, one for each
bit in the byte), it still takes a non-zero amount of time to flip
the spin-state of each electron. This defines the ultimate speed of
both a memory chip and a processor. Note that it takes the same
amount of time to flip the spin-state of the one electron in an atom
of hydrogen, so we don't gain anything by changing atoms.

If we pack the atoms of our megacomputer as dense as possible
without creating a neutron star, there is still a non-zero distance
between atoms. It takes a finite amount of time for a signal to
travel that distance. That defines the overall speed of the
computer.

If we take all the atoms in the universe (oxygen, hydrogen, and all
the others), that defines the ultimate size of a computer. We can
allocate the atoms between memory and processor. Just remember,
the number of atoms is finite; and we must reserve some for the
nuclear power plant that will run this infernal device. Thus, the
memory of our megacomputer is limited.

I saw this concept in some very old technical periodical where the
capacity and speed of an ultimate computer were quantified. The
article was published just before the dawn of PCs, when minicomputers
and microcomputers were being installed with faster capabilities at
far less cost than mainframes. The point is that we can conceive of
finite problems to be solved on a computer that exceed the capacity
of any computer that could ever exist.

As there is indeed a limit to computer power before conjecturing
about a future super-computer cracking a PGP-encrypted message,
we should consider whether that computer could fit into the universe.

Your thoughts on this would be very welcome. I have run out avenues
to explore and worse still my GP will not increase my dose of
Nembies.


You are talking about brute force attacks.

In fact, your message is not random, and there are only a fw things you
probably wrte about, so anyine who really wants t crack it probably
could have some idea of how to do it.

A lot of intelleigence can be gleaned by mointoring traffic density and
source/destination. Even if you can't read it.

Finally, if the CIA want to read your messages, they would probably
break seamlessly into your house and download your encryptions software
onto their own machines. :-)


Dave

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Version: PGP 8.1 - not licensed for commercial use: www.pgp.com

iQA/AwUBQOmBmUoZBF8b6qyZEQLDDwCfSpFufa2mLtpqdFC0iUrdA4 ZUzZUAoPW1
uTHPGj3taWUh2+XV8qru2Nny
=CgxY
-----END PGP SIGNATURE-----

"The Natural Philosopher" wrote in message
...
Big Bill wrote:

[snip]

You are talking about brute force attacks.

In fact, your message is not random, and there are only a fw things
you
probably wrte about, so anyine who really wants t crack it probably
could have some idea of how to do it.

A lot of intelleigence can be gleaned by mointoring traffic density
and
source/destination. Even if you can't read it.

Finally, if the CIA want to read your messages, they would probably
break seamlessly into your house and download your encryptions
software
onto their own machines. :-)

And how often do you have to water it?

Franz

"The Natural Philosopher" wrote in message
...
Big Bill wrote:

[snip]

You are talking about brute force attacks.

In fact, your message is not random, and there are only a fw things
you
probably wrte about, so anyine who really wants t crack it probably
could have some idea of how to do it.

A lot of intelleigence can be gleaned by mointoring traffic density
and
source/destination. Even if you can't read it.

Finally, if the CIA want to read your messages, they would probably
break seamlessly into your house and download your encryptions
software
onto their own machines. :-)

And how often do you have to water it?

Franz

wrote in message
...
On Tue, 3 Aug 2004 13:52:29 +0000 (UTC), "Franz Heymann"
wrote:


"The Natural Philosopher" wrote in message
...
Big Bill wrote:

[snip]

You are talking about brute force attacks.

In fact, your message is not random, and there are only a fw
things
you
probably wrte about, so anyine who really wants t crack it
probably
could have some idea of how to do it.

A lot of intelleigence can be gleaned by mointoring traffic
density
and
source/destination. Even if you can't read it.

Finally, if the CIA want to read your messages, they would
probably
break seamlessly into your house and download your encryptions
software
onto their own machines. :-)

And how often do you have to water it?

A very enigmatic reply!

But it does not answer my question. {:-((

Franz