Security Basics mailing list archives

Re: Encryption Key Question


From: David Heise <dheise () gmail com>
Date: Mon, 28 Feb 2005 11:22:12 -0700

For the specific application that I'm doing, the individual security
of each customer's location isn't really an issue since this is one
minor level of security of the overall application. What are the other
problems with this approach? Or better yet, what is a better approach
that does NOT rely on the user suppling credentials (req), but can be
encoded into the application itself (software only).


On Mon, 28 Feb 2005 09:19:44 -0800, David Gillett <gillettdavid () fhda edu> wrote:
  Hard coding encryption keys into applications is *extremely* poor
practice.  The possibility of extracting the key from the binary is
only one of the problems with this approach.
  We have an application here which is coded that way.  One of my
concerns has to be that every copy of this application at every
customer site uses exactly the same hard-coded key, so the security
of our data can never be much more than that of the application's
LEAST secure customer site.

David Gillett


-----Original Message-----
From: David Heise [mailto:dheise () gmail com]
Sent: Friday, February 25, 2005 4:57 PM
To: security-basics () securityfocus com
Subject: Encryption Key Question


I have a situation which seems to be an endless loop but maybe someone
out here can help me. I'm using SHA-256 has my hash function and AES
as the encryption method. I have a byte array of data and a string
that is the passphrase (currently the string is 306 characters long).
I hash the passphrase and use it to encrypt the data. Since I'm
writing this as part of an application I want to hardcode the
passphrase into the application, however as a string it would be
fairly simple to find it in the complied code.

Here's my question:
What is the best method of storing this passphrase internally in the
application such that it would be as secure as possible?



Unrelated Question:
Is there any security hole in using the data as the key? (other than
it makes it hard/impossible to get it back out)


Thanks
--
David B Heise [dheise () gmail com]
http://students.cs.byu.edu/~dheise




-- 
David B Heise [dheise () gmail com]
http://endofuniverse.blogspot.com      Personal Blog
http://students.cs.byu.edu/~dheise    Personal Web
http://www.stonetempest.com           Company


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