92 lines
3.9 KiB
Plaintext
92 lines
3.9 KiB
Plaintext
From glynn.clements@virgin.net Wed Sep 4 11:37:31 2002
|
|
Return-Path: <glynn.clements@virgin.net>
|
|
Delivered-To: yyyy@localhost.spamassassin.taint.org
|
|
Received: from localhost (jalapeno [127.0.0.1])
|
|
by jmason.org (Postfix) with ESMTP id 761DB16F20
|
|
for <jm@localhost>; Wed, 4 Sep 2002 11:36:58 +0100 (IST)
|
|
Received: from jalapeno [127.0.0.1]
|
|
by localhost with IMAP (fetchmail-5.9.0)
|
|
for jm@localhost (single-drop); Wed, 04 Sep 2002 11:36:58 +0100 (IST)
|
|
Received: from outgoing.securityfocus.com (outgoing2.securityfocus.com
|
|
[66.38.151.26]) by dogma.slashnull.org (8.11.6/8.11.6) with ESMTP id
|
|
g83M8qZ05177 for <jm@jmason.org>; Tue, 3 Sep 2002 23:08:52 +0100
|
|
Received: from lists.securityfocus.com (lists.securityfocus.com
|
|
[66.38.151.19]) by outgoing.securityfocus.com (Postfix) with QMQP id
|
|
204FE8F615; Tue, 3 Sep 2002 15:13:28 -0600 (MDT)
|
|
Mailing-List: contact secprog-help@securityfocus.com; run by ezmlm
|
|
Precedence: bulk
|
|
List-Id: <secprog.list-id.securityfocus.com>
|
|
List-Post: <mailto:secprog@securityfocus.com>
|
|
List-Help: <mailto:secprog-help@securityfocus.com>
|
|
List-Unsubscribe: <mailto:secprog-unsubscribe@securityfocus.com>
|
|
List-Subscribe: <mailto:secprog-subscribe@securityfocus.com>
|
|
Delivered-To: mailing list secprog@securityfocus.com
|
|
Delivered-To: moderator for secprog@securityfocus.com
|
|
Received: (qmail 27519 invoked from network); 3 Sep 2002 19:49:41 -0000
|
|
From: Glynn Clements <glynn.clements@virgin.net>
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=us-ascii
|
|
Content-Transfer-Encoding: 7bit
|
|
Message-Id: <15733.3398.363187.572002@cerise.nosuchdomain.co.uk>
|
|
Date: Tue, 3 Sep 2002 20:28:06 +0100
|
|
To: Yannick Gingras <ygingras@eclipsys.qc.ca>
|
|
Cc: secprog@securityfocus.com
|
|
Subject: Re: Secure Sofware Key
|
|
In-Reply-To: <20020829204345.91D1833986@LINPDC.eclipsys.qc.ca>
|
|
References: <20020829204345.91D1833986@LINPDC.eclipsys.qc.ca>
|
|
X-Mailer: VM 6.94 under 21.4 (patch 9) "Informed Management (RC2)" XEmacs
|
|
Lucid
|
|
|
|
|
|
Yannick Gingras wrote:
|
|
|
|
> I am wondering if there are any techniques to make a CD-Key of the like
|
|
> unbreakable. Either by giving it a cancelation date and a periodic renewal
|
|
> from a server or just by using self md5 signature on the resulting
|
|
> executable. I know it must not be easy because the whole software piracy
|
|
> problem would be resolved but there must be some way to make it really hard
|
|
> to break it. Anyone have hints on this issue ?
|
|
|
|
What do you mean by "CD-Key or the like" (I presume that "of" was a
|
|
typo)? And what do you mean by "unbreakable"?
|
|
|
|
You need to be far more explicit about the problem which you wish to
|
|
solve, and about the constraints involved.
|
|
|
|
Some general points:
|
|
|
|
1. For a conventional "CD key" system, where the actual CDs are
|
|
mass-produced (where you have many identical CDs), and the entire
|
|
system has to work offline, you cannot solve the problem of valid keys
|
|
being "traded" (e.g. included along with bootleg copies of the
|
|
product).
|
|
|
|
If there's an online element involved, you can "tie" keys to a
|
|
specific hardware configuration, as is done (AFAIK) for Windows XP's
|
|
"product activation".
|
|
|
|
2. Anything which uses a symmetric cipher (or hash) is bound to be
|
|
vulnerable to reverse engineering of the validation routines within
|
|
the executable.
|
|
|
|
3. Ultimately, any software mechanism will be vulnerable to
|
|
"cracking", i.e. modifying the software to disable or circumvent the
|
|
validation checks.
|
|
|
|
This can only be prevented by the use of trusted hardware (e.g. a
|
|
Palladium-style system).
|
|
|
|
Most significantly, the data must be supplied in a form which is only
|
|
accessible by that hardware. If anyone can get at the data in a
|
|
meaningful (i.e. unencrypted) form, they can extract the useful parts
|
|
and discard the rest (i.e. any associated protection mechanisms).
|
|
|
|
IOW, you have to "keep the genie in the bottle" at all times. If the
|
|
data can be got at just once (even if it requires the use of dedicated
|
|
hardware such as a bus analyser), it can then be duplicated and
|
|
distributed without limit.
|
|
|
|
--
|
|
Glynn Clements <glynn.clements@virgin.net>
|
|
|