[sf-lug] Notes from the SF-LUG meeting of November 5, 2017

[Rick Moen]

Quoting Daniel Gimpelevich (daniel at gimpelevich.san-francisco.ca.us):

> But, once they are burned, they are read-only, and their hash sums can
> still be verified.

Indeed.  This is both an advantage and a disadvantage, as you know.  I
gives you assurance after burn that they are untouched (short of a new
erase/burn cycle in the case of the RW optical media subvariants), which
is good.  They cannot be reused at all in the case of 'R' variants, and 
only with some extra time and difficult for a limited number of
rewrites, in the case of 'RW' variants, which is bad.

I should note that the integrity of a distro on a USB flash drive can
_equally be verified by checked, at any time, by recalculating the
checksum.

Once upon a time, I hear there were USB flash sticks with write-protect
toggle switches, but those appear to have fallen out of the market.

 Media that are not read-only, such as USB sticks and
> machines on a network, can theoretically be hijacked _after_ this
> verification.

Yes, as with any read-write mass storage.  And checksums can then be
reverified at any time.