🚀 go-pugleaf

uri@watson.ibm.com (Uri Blumenthal) writes:
>    Tripwire supports hooks for up to ten signature routines.  We
>ship it with MD5, Snefru, CRC32, CRC16, MD4, and MD2.  Although
>the CRC routines are not "signatures" in the cryptographic sense,
>they are nice to have since they are considerably faster than the
>more secure algorithms -- which are (hopefully) one-way hash
>functions.

I stated earlier that NONE of these, including MD5, Snefru, and MD4,
are signatures in the cryptographic sense.  A true signature would
require something like RSA or DSA layered on a one-way hash function
like MD5 or SHA.  This would not significantly impact the speed, since
RSA on my Sparc would add less than .01 seconds, whereas MD5 runs at
about a megabyte per second.  Hence as soon as the file is bigger than
10K, the hash will take longer than the signature.  DSA verification
will take considerably longer, but I have an implementation that does
the verification in less than .3 seconds - still acceptable for many
applications.  If this is too slow for checking 100 files on a UNIX
system, then you can apply the hash to a large subset of the files
before finishing with the signature.

Kevin McCurley
Sandia National Laboratories