Re: Sum legl trubs wid TOR en France + more

["Eric H. Jung" <eric.jung@xxxxxxxxx>]

Ringo,

You would have had an idea if you followed and read any of the links I
sent previously.



--- Ringo Kamens <2600denver@xxxxxxxxx> wrote:

> I agree with you about the hops. Thanks for posting the info about
> hard
> drives. I had no idea.
> 
> On Sun May 14 21:58:42 2006, crackedactor@xxxxxxxxxxx <
> crackedactor@xxxxxxxxxxx> wrote:
> >
> >
> > FYI.
> >
> > Hard Disks.. (so abou the length)
> >
> > It is possible to find old data on "scrubbed" disks even with 100's
> of
> > cycles of writeover.
> >
> > The reason is coz of wobble or track shape. Imagine washing machine
> at
> > home, as it spins it wobbles. Now look at your hard disk (get an
> old one out
> > that is past it and open it up!) you'll see the disk rotates at
> high speed.
> > Thoughout its life it has a wobble, just a small one. But this
> wobble
> > changes now and then with time. So when your write/read head lays
> down its
> > magnetic bits on a track it does so with a wobble in it. The track
> itself is
> > wider than the individual bit patterns and so there is only partial
> overlap
> > with past bit patterns. When a disk finds a bits pattern which is
> wrong
> > (from the extra data it stores for check bits)  and it cant recover
> > logically the original pattern it starts to "wipe" away the edges
> of the bit
> > pattern on the track, so as to "clean" the signal. It does this by
> > offsetting the head from the current midpoint of the track. It then
> tries a
> > RE-READ the cleaned track. This is often susuccessful in removing
> "noise"
> > from past bit patterns so as to ge
> > t "clean" read of the last bit pattern. If not successful this
> process
> > might be done any number of times upto the maximum "re-reads"
> specifed in
> > the disk firmware.
> >
> > It is this EXTRA width and the varying wobble that allows data to
> be left
> > on the disk even if "military strength" scrubbing is perfomed by
> software.
> > This is particularly relevant ot data put on when the disk is young
> > remaining there for some months so that the disks bearing wear
> changes the
> > wobble. New bit patterns written over this old bit pattern are
> almost
> > vertaain to bew able to be read - even years later!
> >
> >
> > The more..
> >
> > A while back it was asked if "3 hops is enough". At the time I had
> prblems
> > getting to my email account so here's my 2 cents.
> >
> > The current set 3 hops is a predictable number of hops and because
> of
> > that, the predictability is a DEFINITE weakness in TOR.
> >
> > Its all about ENTROPY (the mathematical concept not the network).
> >
> > If the current systme of a fixed 3 hops was changed to allow 3-6
> hops then
> > I think this would create a much LESS predictable system.
> >
> > Pulling the records on a ALL our TOR servers is possible. And then
> going
> > through them records to see the 3 fixed hops by computer is simple!
> >
> > You then only need to monitor the traget web site to see the EXIT
> server
> > and follow them back. Remeber all US, European, Australasian & many
> Asian
> > govs are now co-operating. so much of the data is ALREADY being
> pooled.
> >
> > BUT if a random 3 to 6 hops was the norm then TOR becomes much less
> > predictable and the computers now have to do mulptile path analysis
> for 3
> > to6 nodes, instead of just 3.
> >
> > Ok so not everyone would need this, or want it and ewe dont know
> the
> > effects on the system.
> >
> > It looks like we have enough middle men to cope so why not give it
> a go.
> >
> > Allow the users to set their min and max hops (3 to 6) and let TOR
> client
> > portion set up random length circuits within those limits.
> >
> > If this was to be tried out it would be best to use 3 to 4 in the
> intial
> > version and see how it goes.
> >
> > Also to hinder timiing attacks and log lookup software it would be
> a good
> > idea to allow the TOR client side to specify random "delay" for the
> hops to
> > put into its packets. Specify max packet delay time and then the
> hop
> > randomly distributes between this and zero delay, some packets
> might then
> > get forwarded in the wrong order, that would further confuse any
> attack
> > software. I say this should be the clients instruction because they
> may not
> > want any delay (eg for streams such as voip).
> >
> > Once again a little at a time, from one version to the next!
> >
> >
> >
> > Ok .. i'm done.
> >
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> >
> >
> >
> >
>