About 33 Bits
This is a blog about my research on privacy and anonymity. The title refers to the fact that there are only 6.6 billion people in the world, so you only need 33 bits (more precisely, 32.6 bits) of information about a person to determine who they are.
This fact has two related consequences. First, a lot of traditional thinking about anonymous data relied on the fact that you can hide in a crowd that’s too big to search through. That notion completely breaks down given today’s computing power: as long as the bad guy has enough information about his target, he can simply examine every possible entry in the database and select the best match.
The second consequence is that 33 bits is not really a lot. If your hometown has 100,000 people, then knowing your hometown gives me 16 bits of entropy about you, and only 17 bits remain. But the real danger is that information about a person’s behavior, which was traditionally not considered personally identifying, can be used to cause serious privacy breaches in a variety of different contexts.
This blog will announce, explain and elaborate on my research as it relates to the above theme. I will also use it as an outlet for my opinions on the broader technical, policy, business and social issues related to my work.