Re: AES-256 encryption

From: cwright@bdosyd.com.au
Date: Sun Aug 19 2007 - 18:11:45 EDT

('binary' encoding is not supported, stored as-is) Hello,
A weak password has nothing to do with this. I did not see any mention that the key was captured, just the file to be decrypted. If the key file is captured this is a separate issue and nothing to do with AES.

There is NO password stored with the encrypted file. A password is used to protect the key, but a key is always to be considered compromised if it is intercepted. The password takes no place in the encryption scheme. I would suggest that you have a read on the encryption protocol specifications.

Regards,
Craig

-----Original Message-----
From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com] On Behalf Of adrian.floarea
Sent: Friday, 17 August 2007 1:49 AM
To: 'R Buena'
Cc: 'Kush Wadhwa'; pen-test@securityfocus.com; forensics@securityfocus.com
Subject: RE: AES-256 encryption

As I say to Kush in a private email, it is almost impossible to crack a file which is encrypted in a proper way with AES.

But, if the password used for encryption is a week password (like 1234 or abcd etc) with a specialized tool you can break the encryption.

Even, if the password is weak some tools cannot decrypt the files, because do not understand the format of the document (for example, if the document is a PKCS#7 structure), so in this case you must use an appropriate tool.

This was the sense of my words.

Hope to help you.

Regards,

 Adrian Floarea, CISA
Business Development Manager
SC CERTSIGN srl
Central Business Park
133, Calea Şerban Vodă St., Building C1, 2nd floor
040205 Bucharest 4, Romania

-----Original Message-----
From: R Buena [mailto:dreamsbig@gmail.com]
Sent: Thursday, August 16, 2007 6:09 PM
To: adrian.floarea
Cc: Kush Wadhwa; pen-test@securityfocus.com; forensics@securityfocus.com
Subject: Re: AES-256 encryption

Just curious, what if the program was KeyPass or PasswordSafe?
and you don't know the passphrase?

On 8/14/07, adrian.floarea <adrian.floarea@uti.ro> wrote:
> Hi Kush,
>
> Please tell me if you know the program which was used for encrypt the file
> and also the used password. If not, I am afraid that will be impossible for
> you to decrypt the file.
>
> There are some good programs for decrypt files (for example Passware) but
> with limited functionalities. For example if was used for encryption a good
> password (more than 6-7 characters, numbers or special characters) it is
> almost impossible to recover the file.
>
> Regards,
>
> Adrian Floarea, CISA
> Business Development Manager
> SC CERTSIGN srlr
> Central Business Park
> 133, Calea &#350;erban Vod&#259; St., Building C1, 2nd floor
> 040205 Bucharest 4, Romania
>
> -----Original Message-----
> From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com] On
> Behalf Of Kush Wadhwa
> Sent: Tuesday, August 14, 2007 1:36 PM
> To: pen-test@securityfocus.com; forensics@securityfocus.com
> Subject: AES-256 encryption
>
> Hello All,
>
> Is there any way to decrypt a file which is AES-256 encrypted? I used
> many of the tools but I was not able to decrypt it. Please help me if
> any one knows how to decrypt it
>
> Regards,
> Kush Wadhwa

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