Censors Delay in Blocking Circumvention Proxies David Fifield & - - PowerPoint PPT Presentation

▶

Jul 03, 2023 350 likes •577 views

Censors Delay in Blocking Circumvention Proxies David Fifield & Lynn Tsai University of California, Berkeley Tor (The Onion Router) Anonymous network Poorly suited for censorship circumvention Including bridges + pluggable transports

SLIDE 1

Censors’ Delay in Blocking Circumvention Proxies

David Fifield & Lynn Tsai University of California, Berkeley

SLIDE 2

Tor (The Onion Router)

Anonymous network Poorly suited for censorship circumvention Including bridges + pluggable transports

Unlisted nodes that are difficult to discover

Default bridges

SLIDE 3

SLIDE 4

Internet Censors and Circumvention Proxy Servers

Length of delay Not intuitive Methods of discovery

SLIDE 5

SLIDE 6

SLIDE 7

SLIDE 8

SLIDE 9

Internet Censors and Circumvention Proxy Servers

Length of delay Not intuitive Methods of discovery

SLIDE 10

Methodology

Script that probes bridges to test for reachability China, Iran, US

SLIDE 11

SLIDE 12

Results

Number of days it took to block Orbot Blocking time of day

SLIDE 13

SLIDE 14

Results

Number of days it took to block Orbot Blocking time of day

SLIDE 15

Blocking Time of Day Graph

SLIDE 16

Rates of Reachability Graph

SLIDE 17

Further Questions and Steps

Bridge address discovery Blocking delay is on the order of days Traceroutes Other countries

SLIDE 18

SLIDE 19

Further Questions and Steps

Bridge address discovery Blocking delay is on the order of days Traceroutes Other countries https://www.bamsoftware.com/proxy-probe/

SLIDE 20

Thanks!

Percy Alpha Nima Fatemi Linus Nordberg Henry de Valence & Others who choose to stay anonymous

SLIDE 21