MassBrowser Unblock cking the Censored Web fo for the Masses, by - PowerPoint PPT Presentation

MassBrowser Unblock cking the Censored Web fo for the Masses, by the Masses Milad Nasr, Hadi Zolfaghari, Amir Houmansadr, Amirhossein Ghafari University of Massachusetts, Amherst 1

Internet Censorship 2

Censorship Circumvention Tools 3

Shortcomings of Current Designs Easy to Block Costly Poor QoS No User- Hard to Control Deploy 4

Key Reason: They Bundle Properties Circumvention Anonymity Privacy 5

Our Observation: The Mass of Users Just Want Circumvention 6

Our Approach Design a System Optimized for Circumvention Privacy/Anonymity provided optional 7

MassBrowser 8

Key Design Principles • Optimizing load on proxies • Volunteer based proxies • Clients help other clients • User-adjustable privacy/anonymity • Incentivizing volunteers • Cost optimization 9

Key Design Principles • Optimizing load on proxies • Volunteer based proxies Optimizing only • Clients help other clients on circumvention • User-adjustable privacy/anonymity • Incentivizing volunteers • Cost optimization 10

Key Design Principles • Optimizing load on proxies • Volunteer based proxies • Clients help other clients • User-adjustable privacy/anonymity • Incentivizing volunteers • Cost optimization 11

Proxy-based Systems Block it! PNG from FreePik Destination Proxy 12

CacheBrowsing twitter.com Contents on CDN 13

Operator Optimizing Load on Proxies PolicyManager SessionManager MassBrowser HTTPS Channel CacheBrowsing Client Yes Is Is Is Available Yes CacheBrowsable? MassBrowsable? No Censored? Session Controlling Request a new Session signals CDN www.bbc.com Yes No Yes No 41% of Top 1000 Alexa Proxy Tor Connect Proxy through CacheBrowse through Directly Buddy website contents are MassBrowser Buddy cache browsable Proxy via 14 Buddies Encryption and Obfuscation Content Publisher CDN Server

Key Design Principles • Optimizing load on proxies • Volunteer based proxies • Clients help other clients • User-adjustable privacy/anonymity • Incentivizing volunteers • Cost optimization 15

China Censored Region 1 Operator Open Internet Clients Turkey Censored Region 2 Buddies 16 Clients

Clients Helping Each Other! About 90% of political and 1 . 0 news censored Cumulative Fraction contents are 0 . 8 country specific Any 0 . 6 News More than 60% Political 0 . 4 of censored Personal Websites contents are Pornography 0 . 2 country specific Extremist 0 . 0 5 10 15 Countries 17

An Example! China Iran Only 18 websites are 91 blocked in all three 27852 1564 18 29 205 156 *Top 1M websites 18 Turkey

Key Design Principles • Optimizing load on proxies • Volunteer based proxies • Clients help other clients • Incentivizing volunteers • User-adjustable privacy/anonymity • Cost optimization 19

Incentivizing Volunteer Proxies Buddies can whitelist! Buddies can control usage! 20

Key Design Principles • Optimizing load on proxies • Volunteer based proxies • Clients help other clients • Incentivizing volunteers • User-adjustable privacy/anonymity • Cost optimization 21

Users Can Trade off QoS vs. Privacy • Cost: • MassBrowser is about 200 times cheaper than Tor’s meek • Performance: *experiments done in Iran 22

The Current State of The Project 23

Development Status • Near three years of active development! • 100K lines of code • More than 10 people helped in the development • Undergoing code review and security audit by a third-party • Internationalization is undergoing 24

Working Client and Buddy Coming Soon! 25

Currently Invitation-based Only 26

We Need Your Help! • If you are in an uncensored region: • Become a Buddy! • Become an early adopter • Get involved with the development 27

Thanks to so many people who helped in the testing and development of MassBrowser • “It's very good to use!!!!!!” • “It's very very interesting and amazing~” • “Hello, I am in China. I am using mass browser and tor browser now. Now I can use the websites blocked by the Chinese government, and the speed is very good. Thank you very much.” • “Great relaying capability!” • “Great, works really well!” • … 28

COMPUTING FOR THE COMMON GOOD MassBrowser.cs.umass.edu @massbrowser Join us! Milad Nasr milad@cs.umass.edu https://people.cs.umass.edu/~milad/ | @srxzr

Domain Fronting Destination 30