Subject: Re: cgd and replay
To: Ted Unangst <tedu@zeitbombe.org>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: tech-security
Date: 05/10/2005 21:33:58
In message <Pine.BSO.4.61.0505102117470.6013@af.pbqrshfvbavf.pbz>, Ted Unangst
writes:
>it's my understanding that cgd doesn't provide any protection against
>replay or other injection attacks. this wasn't really addressed in the
>paper, except in passing. was it considered and rejected as outside
>problem space? too difficult? essentially, does anybody care and how
>much? if i wanted to authenticate the data on the disk, what's the best
>approach?
>
>attack scenario is kinda like this. some kind of network where the users
>trust their laptops, but possibly not the large usb drive left in the
>office over night, and want to detect tampering.
>
The best scheme I've seen for integrity protection of encrypted disks
is described in
# Space-efficient block storage integrity
A. Oprea, M. K. Reiter and K. Yang
In Proceedings of the 2005 ISOC Network and Distributed System Security
Symposium, pages 17-28, February 2005.
http://www.ece.cmu.edu/~reiter/papers/2005/NDSS.pdf
--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb