Steps Toward Online Freedom of Information

Departmental Seminar
Speaker's Name: 
Dr. Eugene Vasserman
Speaker's From Label: 
Kansas State University
Date & Time: 
Friday, October 7, 2011 - 12:30pm
126 Nichols
Talk Summary: 

This talk explores the problem space of censorship resistance, with the
explicit goal of designing censorship-resistant systems and protecting
their users from powerful adversaries who control much of the common
network (i.e. Internet). We will discuss some recent work in the field,
and focus on two systems in greater depth -- one that provides
membership concealment (MCON), i.e. hides the real-world identities of
participants, and another that builds upon the first to provide robust
content storage (CROPS).

The fundamental requirement of censorship resistance is content
availability and discoverability -- it should be easy for users to find
and access documents. At the same time, participating storage providers
should be unaware of what they are storing to preserve plausible
deniability, but how do we maintain a searchable index of content for
users and yet hide it from storage providers? One possible solution is
to separate file data, metadata, and encryption keys such that someone
searching for information about a specific topic can retrieve all three
components and reconstruct the file, but someone who only stores at most
two components can neither determine the nature of the file content nor
locate the missing component. Combined with a membership concealing
layer, this storage system design is censorship resistant and
exceptionally robust to failure, providing 99.99998666% reliability even
if 70% of participants have left or failed.