DES decryption for des_enc of Tim Hudson and Eric Young

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Tom

Hey experts,

I have to write some classes doing communications with a device
controlled via RS 232. Everthing is working well, but the data the
device is sending back is encrypted.

As I have found out today, the firmware is using algorithms which are
compatible to the algorithms created by Eric Yound and Tim Hudson a
couple of years ago.

I have studied DESCryptoServiceProvider and found, that handling of
this provider is very easy. The device is using easy ECB encryption
and the decryption should be just a few lines of code.

The problem: I just know a string (char) phrase which is used by the
device to generate a key, for example "12345678".

Is there ANYONE in the univers, who knows the code of Eric Young and
Tim Hudson (probably themselves - email addresses in source are not
correct anymore) and can help me using DESCryptoServiceProvider with
my string phrase to decrypt information of the device (in CSharp c#)
??

Folks, I am not trying to crack anything - the device is just a few
years old and theres nobody left to help me working with it.

Thanks for any info which could help me researching or solving.

Mr. Nicolas Paladino - probably you know any further infos ??

THANKS.

Tom
 
Tom said:
Hey experts,

I have to write some classes doing communications with a device
controlled via RS 232. Everthing is working well, but the data the
device is sending back is encrypted.

As I have found out today, the firmware is using algorithms which are
compatible to the algorithms created by Eric Yound and Tim Hudson a
couple of years ago.

I have studied DESCryptoServiceProvider and found, that handling of
this provider is very easy. The device is using easy ECB encryption
and the decryption should be just a few lines of code.

The problem: I just know a string (char) phrase which is used by the
device to generate a key, for example "12345678".

Is there ANYONE in the univers, who knows the code of Eric Young and
Tim Hudson (probably themselves - email addresses in source are not
correct anymore) and can help me using DESCryptoServiceProvider with
my string phrase to decrypt information of the device (in CSharp c#)
??

Folks, I am not trying to crack anything - the device is just a few
years old and theres nobody left to help me working with it.

Thanks for any info which could help me researching or solving.

Mr. Nicolas Paladino - probably you know any further infos ??

THANKS.

Tom
Click to expand...

I think you can find Tim's email address here:
http://www2.psy.uq.edu.au/~ftp/Crypto/

/Fredrik
 
Frederik,

thanks for the information but the mailadress given on that site is
not valid anymore (I#ve tried to post a message)- cryptosoft.com
domain does not really exist.

I think my prolbem is not really a problem, but a misunderstanding:

If I geive an 8 byte key to DESCryptoServiceProvider(), the provider
will calculate all necessary schedules and it will work correct - this
is why I could not find any key generator -> it is not needed !

This problem is now SOLVED - it did not exist (only in my head).

Thanks for any comments.

Tom
 
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