Winzip's 256bit-AES encryption & self-extracting files

Winzip's 256bit-AES encryption & self-extracting files
Secure Home | Search | About
Login Password
Register Now! Lost Password?
 General Computer Security    Post an article   get this group's latest topics as an RSS feed add this group's latest topics to your My MSN content add this group's latest topics to your My Yahoo content add this group's latest topics to your Google content
Subject Author Date
Winzip's 256bit-AES encryption & self-extracting files Bakko 12-29-2007
Posted by Bakko on January 3, 2008, 3:24 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
>>
>> That's why I want a very high level of data encryption. My
>> question to the group is if a high level of encryption is used
>> (like AES-256) as part of a SELF-EXTRACTING file then does the
>> encryption provided by AES-256 get compromised?
>>
>> Do you have any info on this?



wrote:
>
> Unless the NSA has you targeted, it is near impossible for any
> normal user, even a hacker, to get at the contents of your
> encrypted .zip file. For NSA, you'll probably expire when they
> crack it.



Vanguard, I may not be making my question clear enough.

I accept that AES 256 is plenty secure enough and that Winzip's
implementation of it is good for .ZIP files.

The QUESTION I am asking is this:

Is the security of an AES 256 self-extracting
zip .EXE as good as an AES 256 .ZIP file?

I would like to know if a self extracting EXE has any weaknesses
compared to a ZIP (when both are encrypted).


Posted by VanguardLH on January 3, 2008, 6:11 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
> I would like to know if a self extracting EXE has any weaknesses
> compared to a ZIP (when both are encrypted).


The contents (payload) first get zipped using the encryption. Then a
wrapper is used which is the .exe file. There isn't any protection on
the wrapper. Anyone can run it. However, they will still get queried
for the password to decrypt the payload - the same password that must
be used if all that got delivered was the .zip payload. Whether you
use a separate unzip utility, like Winzip, 7-Zip, UltimateZip, or you
use a wrapper .exe that was included in the delivery, the payload is
just as encrypted.

The .exe wrapper isn't what gets protected. It's the .zip payload
that is encrypted. The wrapper is literally just tacked on with the
payload as a huge data section of the program.


Posted by Bakko on January 13, 2008, 12:48 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
wrote:

>> I would like to know if a self extracting EXE has any weaknesses
>> compared to a ZIP (when both are encrypted).
>
>
> The contents (payload) first get zipped using the encryption. Then
> a wrapper is used which is the .exe file. There isn't any
> protection on the wrapper. Anyone can run it. However, they will
> still get queried for the password to decrypt the payload - the
> same password that must be used if all that got delivered was the
> .zip payload. Whether you use a separate unzip utility, like
> Winzip, 7-Zip, UltimateZip, or you use a wrapper .exe that was
> included in the delivery, the payload is just as encrypted.
>
> The .exe wrapper isn't what gets protected. It's the .zip payload
> that is encrypted. The wrapper is literally just tacked on with
> the payload as a huge data section of the program.
>

Vanguard, that's a very useful reply. Thanks.

I understand there is (1) a wrapper and (2) a payload.
Where does it keep the routine for testing the user-entered key?

Is the key-test actually a part of the payload or is the key-test a
third component (which is accessed by the dialog/prompts of the
wrapper)?

Posted by Sebastian G. on January 13, 2008, 2:25 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
Bakko wrote:


> I understand there is (1) a wrapper and (2) a payload.
> Where does it keep the routine for testing the user-entered key?


The routine is in the wrapper, the value to check against is considered as
payload. Typically a salted hash to check for key pretty fast, and then a
keyed MAC for integrity of the rest of the payload.

Posted by Volker Birk on January 4, 2008, 3:16 am
If you were  Registered and logged in, you could reply and use other advanced thread options
> I accept that AES 256 is plenty secure enough and that Winzip's
> implementation of it is good for .ZIP files.

Why the latter. Do you have the source code?

Yours,
VB.
--
The file name of an indirect node file is the string "iNode" immediately
followed by the link reference converted to decimal text, with no leading
zeroes. For example, an indirect node file with link reference 123 would
have the name "iNode123". - HFS Plus Volume Format, MacOS X

Similar ThreadsPosted
What is the earliest version with full harddisk encryption (not only files) ? July 27, 2005, 9:05 am
Searching tool for FULL disc encryption (not only volume files) July 28, 2005, 11:06 am
SSL/https De-encryption July 6, 2004, 9:15 am
NTFS Encryption April 26, 2005, 6:31 pm
Encryption Key Storage August 25, 2005, 8:09 am
Email Encryption September 17, 2005, 12:20 am
Encryption size October 25, 2005, 3:13 am
Determine what encryption was used April 18, 2006, 8:52 am
Determine what encryption was used April 28, 2006, 4:50 am
Encryption for Powerpoint? May 19, 2006, 11:34 pm

The site map in XML format XML site map

Contact Us | Privacy Policy