1994-06-02 - Faster way to deescrow Clipper

Header Data

From: Mike Ingle <MIKEINGLE@delphi.com>
To: cypherpunks@toad.com
Message Hash: 5143fe2b25f6e28fb47268c6c28a19ba00ea52de98ee9924424d9c12ef920384
Message ID: <01HD2TUJI8NC95Q50V@delphi.com>
Reply To: N/A
UTC Datetime: 1994-06-02 23:39:35 UTC
Raw Date: Thu, 2 Jun 94 16:39:35 PDT

Raw message

From: Mike Ingle <MIKEINGLE@delphi.com>
Date: Thu, 2 Jun 94 16:39:35 PDT
To: cypherpunks@toad.com
Subject: Faster way to deescrow Clipper
Message-ID: <01HD2TUJI8NC95Q50V@delphi.com>
MIME-Version: 1.0
Content-Type: text/plain


The attack posted here uses a brute-force search to find a phony LEAF
which has a valid checksum. Instead, why not just initialize the chip
with a session key and get the LEAF. Reset the chip and initialize it
with a different session key, but send the first LEAF instead of the
second one. The LEAF would look good unless you tried to decrypt the
session key. The wrong-IV problem would remain. The NSA should have
designed the Clipper so that, if the IV was wrong, the chips would not
accept the LEAF. They also should have used a much larger (32-bit or
even 64-bit) checksum.

--- Mike
 

Thread

• Return to June 1994

• Return to “Derek Atkins <warlord@MIT.EDU>”
• Return to “Edward Hirsch <diseased@panix.com>”
• Return to “Mike Ingle <MIKEINGLE@delphi.com>”
• Return to “nelson@crynwr.com (Russell Nelson)”

• Return to ““Perry E. Metzger” <perry@imsi.com>”

• 1994-06-02 (Thu, 2 Jun 94 16:39:35 PDT) - Faster way to deescrow Clipper - Mike Ingle <MIKEINGLE@delphi.com>
  • 1994-06-03 (Thu, 2 Jun 94 17:01:18 PDT) - Re: Faster way to deescrow Clipper - Derek Atkins <warlord@MIT.EDU>
    • 1994-06-03 (Thu, 2 Jun 94 18:45:30 PDT) - Re: Faster way to deescrow Clipper - nelson@crynwr.com (Russell Nelson)
      • 1994-06-04 (Fri, 3 Jun 94 21:00:54 PDT) - NYT article - Edward Hirsch <diseased@panix.com>
        • 1994-06-04 (Fri, 3 Jun 94 23:05:14 PDT) - Re: NYT article - Derek Atkins <warlord@MIT.EDU>
  • 1994-06-03 (Fri, 3 Jun 94 05:06:39 PDT) - Re: Faster way to deescrow Clipper - “Perry E. Metzger” <perry@imsi.com>
    • 1994-06-03 (Fri, 3 Jun 94 05:57:00 PDT) - Re: Faster way to deescrow Clipper - “Perry E. Metzger” <perry@imsi.com>