Re: Recognizing Encryption Type

[Neil <neil () voidfx net>]

On 2/3/2006 1:12 PM, Vladimir B. Kropotov wrote:
> Hi Folks
>
> mam> I was just wondering if there was a feasible way in order to obtain the
> mam> encryption type of a specific file. Could this be done using a third
> mam> party program that would inspect the running process of the encryptor as
> mam> it is working on the input file and after that examining the resulting
> mam> output? If not using this procedure, would the attacker be able to
> mam> identify the encryption type by reverse engineering the encryptor program?
>
> Basically strong cryptography protocols secutity MUSTN'T change if
> protocol is known for attacker. All strong cryptography protocols
> consider that encryption method is known.
>
> Another poing of view: if you use system that not suited for security
> level (e.g. B2) you mustn't care about attacker which "able to identify
> the encryption type", becuase your WHOLE system is strong as your
> weaknest link. If  atackers program would inspect the running process of the encryptor as
> it is working on the input file - you SHOULDN'T care about encryption
> type, you screwed up and loose all your sensitive information.
>
> Direct Answer.
> It's possible, especially if you can control input and output.
> For more information ask Russian and US experts www.fsb.ru and
> www.cia.gov :-D
>
>
>
> Regards
> Vladimir B.Kropotov

If well, nothing is safe if you can inspect the process as it run,
because you can grab the key out of the process (even if it encrypts the
key as well, because _that_ encryption has to come from somewhere, and
the attacker can inspect that too).

But with strong encryption, assuming you use a different key each time,
the type of encryption is irrelevant.

-- 
Neil.
http://voidfx.net
"As scarce as truth is, the supply has always been in excess of the demand."
--Josh Billings

---------------------------------------------------------------------------
EARN A MASTER OF SCIENCE IN INFORMATION ASSURANCE - ONLINE
The Norwich University program offers unparalleled Infosec management 
education and the case study affords you unmatched consulting experience. 
Tailor your education to your own professional goals with degree 
customizations including Emergency Management, Business Continuity Planning, 
Computer Emergency Response Teams, and Digital Investigations. 

http://www.msia.norwich.edu/secfocus
---------------------------------------------------------------------------