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Science Forum Index » Cryptography Forum » Quick basic question
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| Cay @ OE6 |
 Posted: Sat Jan 03, 2004 8:43 pm |
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Guest
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Assuming one has access to a cyphertext as well as plaintext version of an
encrypted file, is it possibile to determine the private key?
If so, look at this scenario: A WinXP Laptop that has the entire harddisk
encrypted with the built in encryption scheme. Couldn't an attacker simply
get the cyphertext version of, say, a windows system file, get a plaintext
version from his own installation of windows, determine the key and open it
all up?
(I'm aware he could also simply brute force the user account's password in
most cases)
TIA
-Cay |
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| Andrew Swallow |
| Posted: Sat Jan 03, 2004 8:43 pm |
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"Cay @ OE6" <wit@nil.nil> wrote in message
news:3ff7809d$0$16002$91cee783@newsreader01.highway.telekom.at...
Quote: Assuming one has access to a cyphertext as well as plaintext version of an
encrypted file, is it possibile to determine the private key?
If so, look at this scenario: A WinXP Laptop that has the entire harddisk
encrypted with the built in encryption scheme. Couldn't an attacker simply
get the cyphertext version of, say, a windows system file, get a plaintext
version from his own installation of windows, determine the key and open
it
all up?
(I'm aware he could also simply brute force the user account's password in
most cases)
Practical answer - NO.
The encryption algorithms/equations used in 3DES, AES, RSA
and DH cannot be solved. Inverting algorithms that our cleverest
mathematicians cannot invert is the skill of the cryptographer.
Andrew Swallow |
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| Andrew Swallow |
| Posted: Sat Jan 03, 2004 8:43 pm |
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Guest
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"Cay @ OE6" <wit@nil.nil> wrote in message
news:3ff7809d$0$16002$91cee783@newsreader01.highway.telekom.at...
Quote: Assuming one has access to a cyphertext as well as plaintext version of an
encrypted file, is it possibile to determine the private key?
If so, look at this scenario: A WinXP Laptop that has the entire harddisk
encrypted with the built in encryption scheme. Couldn't an attacker simply
get the cyphertext version of, say, a windows system file, get a plaintext
version from his own installation of windows, determine the key and open
it
all up?
(I'm aware he could also simply brute force the user account's password in
most cases)
Practical answer - NO.
The encryption algorithms/equations used in 3DES, AES, RSA
and DH cannot be solved. Inverting algorithms that our cleverest
mathematicians cannot invert is the skill of the cryptographer.
Andrew Swallow |
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| Back to top |
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| Andrew Swallow |
| Posted: Sat Jan 03, 2004 8:43 pm |
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Guest
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"Andrew Swallow" <am.swallow@eatspam.btinternet.com> wrote in message
news:bt853v$ci2$1@titan.btinternet.com...
Quote: "Cay @ OE6" <wit@nil.nil> wrote in message
news:3ff7809d$0$16002$91cee783@newsreader01.highway.telekom.at...
Assuming one has access to a cyphertext as well as plaintext version of
an
encrypted file, is it possibile to determine the private key?
If so, look at this scenario: A WinXP Laptop that has the entire
harddisk
encrypted with the built in encryption scheme. Couldn't an attacker
simply
get the cyphertext version of, say, a windows system file, get a
plaintext
version from his own installation of windows, determine the key and open
it
all up?
(I'm aware he could also simply brute force the user account's password
in
most cases)
Practical answer - NO.
The encryption algorithms/equations used in 3DES, AES, RSA
and DH cannot be solved. Inverting algorithms that our cleverest
# Inventing (sp)
mathematicians cannot invert is the skill of the cryptographer.
Andrew Swallow
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| Nick |
| Posted: Sun Jan 04, 2004 9:43 pm |
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On Sun, 04 Jan 2004 04:37:32 +0000, Andrew Swallow wrote:
Quote: "Andrew Swallow" <am.swallow@eatspam.btinternet.com> wrote in message
news:bt853v$ci2$1@titan.btinternet.com...
"Cay @ OE6" <wit@nil.nil> wrote in message
news:3ff7809d$0$16002$91cee783@newsreader01.highway.telekom.at...
Assuming one has access to a cyphertext as well as plaintext version of
an
encrypted file, is it possibile to determine the private key?
If so, look at this scenario: A WinXP Laptop that has the entire
harddisk
encrypted with the built in encryption scheme. Couldn't an attacker
simply
get the cyphertext version of, say, a windows system file, get a
plaintext
version from his own installation of windows, determine the key and open
it
all up?
(I'm aware he could also simply brute force the user account's password
in
most cases)
Practical answer - NO.
The encryption algorithms/equations used in 3DES, AES, RSA
and DH cannot be solved. Inverting algorithms that our cleverest
# Inventing (sp)
I think he actually meant inverting. although cryptographer should
probably be cryptanalyst in the next sentence.
Quote: mathematicians cannot invert is the skill of the cryptographer.
Andrew Swallow
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