🚀 go-pugleaf

In article <Bx5uwo.30F@mentor.cc.purdue.edu> spaf@cs.purdue.EDU (Gene Spafford) writes:
>This is to announce the first public release of "Tripwire."
>
>Tripwire is an integrity-monitor for Unix systems.  It uses several
>checksum/signature routines to detect changes to files, as well as

I would like to comment that this use of the term "signature" should
not be confused with the much stronger term of signature that is
common in cryptology literature.  The "signatures" provided in
Tripwire appear to be nothing more than checksums (also known as
cryptographically secure hash functions).  The difference is that a
checksum for a given file can be produced easily by anyone, and
therefore verified easily by anyone.  In cryptology literature, the
term signature is used to denote something that is hard to create
without secret information, but is easily verifiable by anyone.  MD5
is a checksum, whereas the proposed DSS provides a digital signature.

The major difference in practice is that if a system critical file
like /etc/passwd can be changed, then presumably a checksum of that
file can also be changed.  On the other hand, a legitimate digital
signature like DSS or RSA cannot be produced when the file is changed
without access to some secret information that is presumably not even
stored on the machine (or any machine).  You will notice that the
Tripwire database needs to be placed in a secure location like on
another machine with a read-only disk.  If a true digital signature
algorithm was used (like DSS or RSA), then this would not be
necessary.

Kevin McCurley