Preventing date rollback

[John F Haugh II]

In article <1959 at necisa.ho.necisa.oz> boyd at necisa.ho.necisa.oz (Boyd Roberts) writes:
>How are you going to stop the place where it's written from being re-witten?

Among other things, by using data encryption or something similiarly nasty
like cryptographic checksums.  [ All of which can also be defeated, but at
a slightly higher cost. ]
-- 
John F. Haugh II                             UUCP: ...!cs.utexas.edu!rpp386!jfh
Ma Bell: (512) 832-8832                           Domain: jfh at rpp386.cactus.org