Re: [2.6 patch] let CONFIG_SECCOMP default to n

Pavel Machek
2006-07-13T21:30:09Z

Hi!

> > Actually measuring time through the network is extremely doable given
> > enough samples as is communication through delay perturbation. A good
> > viterbi encoder/decoder will fish a signal out of very high noise. Yes
> > you pay a lot in data rate at that point but it works.
>
> Currently the bandwidth is free, I'll charge for the transaction
> associated bandwidth only if I'm forced to (which would happen quickly
> if people starts doing the above ;).
>
> The way the current transactions are running as we speak, is not like
> in a full peer to peer system. It's half peer to peer, a trusted node
> always sits in between buyer and seller. I need this for a multitude
> of reasons (I could offload the middle node in a p3p system that is
> reliable as long as only 1 of the 3 is malicious but it's certainly
> more secure if the node in the middle is fully trusted so I'll try to
> avoid that). So if you are right, my trusted node will simply add
> /dev/urandom delay as needed before forwarding any packet, to prevent
> any meaningful measurement. Any network side channel can be solved in
> a few liner patch and very quickly.

Actually random delays are unlike to help (much). You have just added
noise, but you can still decode original signal...

--
Thanks for all the (sleeping) penguins.