Multiple pass cascading fragmentation 0362 is applied
if the user selects the heightened security option. In this case, the user is asked to
specify a number of cascades 0360, ranging from two to seven. Cascading fragmentation
0362 provides ultra high privacy because the content from the original data files 0220
is rearranged and fragmented repeatedly. After each fragmentation run, step 1740, the
resulting composite files 0250 are gathered and used as input for another run of
fragmenting 1740. A useful metaphor is to liken this repetitive process to blowing
up a building [ed.: see note at bottom of this page],
sweeping up the rubble, blowing that up, gathering the now-much-finer
rubble, exploding that, and so forth for up to seven iterations. The difference
from the building explosion metaphor is that the original data files 0220 can be
reconstituted quickly, provided only that the last set in its entirety of
composite files 0250, an extended final index file 0260, and one reconstitution
file 0270 for each iteration (or cascade) are available to the authorized
computer and user. Security is eminently higher, because a person who is
denied access to even one element of the outputs listed above is utterly
incapable (with intensive reverse engineering or even complete source code
for the system and method) to retrieve the original data files 0220. For
example, if even one of the reconstitution files 0270 is unobtainable,
unauthorized users have no hope of making sense of outputs 0250 that may
come into their hands.
Returning to FIGURE 03, the user who wishes even greater
security is always free to perform multiple single pass iterations 0361, manually setting
output from one session as input for the next, with different passwords 0330 for each,
for as many iterations / cascades 0360 as desired -- well beyond the automated maximum
of seven.
NOTE: The entire patent was written prior to September
11, 2001. I find a certain discomfort now with the metaphor of blowing up buildings. Consider an
alternative metaphor for cascading -- repetitive use of a cross-cut paper shredder. Suppose on the
first round you feed in 5000 standard letter-size sheets. The average output might be thumbnail
size. Gather the output, mix it thoroughly and feed it through the shredder a second time.
The result this time is confetti. Mix it again, feed it into the cross-cup paper shredder again.
The average size of output might be the equivalent of a single character. Repeat up to seven
iterations and the result would be paper powder. Of course, both the paper shredding and the exploded
building metaphors fall short, since Pryvit can reconstitute the original files, no matter
how often privatizing has been repeated.
