[tor-bugs] #5023 [Pluggable transport]: Morpher pluggable transport: Select algorithm for packet size morphing

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#5023: Morpher pluggable transport: Select algorithm for packet size morphing
---------------------------------+------------------------------------------
 Reporter:  asn                  |          Owner:  asn  
     Type:  task                 |         Status:  new  
 Priority:  normal               |      Milestone:       
Component:  Pluggable transport  |        Version:       
 Keywords:                       |         Parent:  #4680
   Points:                       |   Actualpoints:       
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Old description:

> This is a ticket to resolve a) of comment:1:ticket:4680 :
>
> We should evaluate whether the final morpher transport should use 'random
> sampling', or 'morphing matrices' to select a packet's final packet size.
>
> In 'random sampling', you have a packet size probability distribution of
> a target protocol, and you pick a random variable, and then you shape
> your packet to be of that size.
> By 'morphing matrices', I mean the technique described in the paper
> Traffic Morphing: An efficient defense against statistical traffic
> analysis which attempts to minimize the padding overhead imposed by
> packet size shaping.
>
> Since our morpher transport will try to turn Tor traffic into HTTPS
> traffic, as far as packet sizes are concerned, we should evaluate whether
> the 'morphing matrices' method is worth it. We can build a tool that uses
> both methods on a couple thousand packets, and see which method is more
> effective. If 'morphing matrices' is indeed more effective, we should see
> whether it's effective enough to justify its troublesome implementation.
>
> I stupidly attached all relevant files to #4680, but let's continue the
> discussion here to avoid flooding #4680 more.

New description:

 This is a ticket to resolve a) of comment:1:ticket:4680 :

 We should evaluate whether the final morpher transport should use 'random
 sampling', or 'morphing matrices' to seTrac Powered

 Plect a packet's final packet size.

 In 'random sampling', you have a packet size probability distribution of a
 target protocol, and you pick a random variable, and then you shape your
 packet to be of that size.
 By 'morphing matrices', I mean the technique described in the paper
 Traffic Morphing: An efficient defense against statistical traffic
 analysis which attempts to minimize the padding overhead imposed by packet
 size shaping.

 Since our morpher transport will try to turn Tor traffic into HTTPS
 traffic, as far as packet sizes are concerned, we should evaluate whether
 the 'morphing matrices' method is worth it. We can build a tool that uses
 both methods on a couple thousand packets, and see which method is more
 effective. If 'morphing matrices' is indeed more effective, we should see
 whether it's effective enough to justify its troublesome implementation.

 I stupidly attached all relevant files to #4680, but let's continue the
 discussion here to avoid flooding #4680 more.

--

Comment(by asn):

 Replying to [comment:2 asn]:
 > Note that currently the plot titles are inversed. So
 attachment:500_cs.png:ticket:4680 is really the C->S plot, even if the
 title says "Server->Client: 500 packets". For now, trust the filenames
 more than the titles.
 >
 > I'll try to re-plot them with correct titles, but it's gonna take me
 some time.
 Trac Powered

 Fixed. The plot titles should now be correct.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5023#comment:4>
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