February 28, 2017

Archives for March 2010

Pseudonyms: The Natural State of Online Identity

I’ve been writing recently about the problems that arise when you try to use cryptography to verify who is at the other end of a network connection. The cryptographic math works, but that doesn’t mean you get the identity part right.

You might think, from this discussion, that crypto by itself does nothing — that cryptographic security can only be bootstrapped from some kind of real-world identity verification. That’s the way it works for website certificates, where a certificate authority has to check your bona fides before it will issue you a certificate.

But this intuition turns out to be wrong. There is one thing that crypto can do perfectly, without any real-world support: providing pseudonyms. Indeed, crypto is so good at supporting pseudonyms that we can practically say that pseudonyms are the natural state of identity online.

To explain why this is true, I need to offer a gentle introduction to a basic crypto operation: digital signatures. Suppose John Doe (“JD”) wants to use digital signatures. First, JD needs to create a private cryptographic key, which he does by generating some random numbers and combining them according to a special geeky recipe. The result is a unique private key that only JD knows. Next, JD uses a certain procedure to determine the public key that corresponds to his private key. He announces the public key to everyone. The math guarantees that (1) JD’s public key is unique and corresponds to JD’s private key, and (2) a person who knows JD’s public key can’t figure out JD’s private key.

Now JD can make digital signatures. If JD wants to “sign” a certain message M, he combines M with JD’s private key in a special way, and the result is JD’s “signature on M”. Now anybody can verify the signature, using JD’s public key. Only JD can make the signature, because only JD knows JD’s private key; but anybody can verify the signature.

At no point in this process does JD tell anybody who he is — I called him “John Doe” for a reason. Indeed, JD’s public key is a perfect pseudonym: it conveys nothing about JD’s actual identity, yet it has a distinct “owner” whose presence can be verified. (“You’re really the person who created this public key? Then you should be able to make a signature on the message ‘squeamish ossifrage’ for me….”)

Using this method, anybody can make up a fresh pseudonym whenever they want. If you can generate random numbers and do some math (or have your computer do those things for you), then you can make a fresh pseudonym. You can make as many as you want, without needing to coordinate with anybody. This is all easy to do.

These methods, pseudonyms and signatures, are used even in cases where we want to verify somebody’s real-world identity. When you connect to (say) https://mail.google.com, Google’s web server gives you its public key — a pseudonym — along with a digital certificate that attests that that public key — that pseudonym — belongs to Google Inc. Binding public keys — pseudonyms — to real-world identities is tedious and messy, but of course this is often necessary in practice.

Online, identities are hard to manage. Pseudonyms are easy.

China, the Internet and Google: what I planned to say

In the run-up to and aftermath of Google’s decision yesterday to remove its Chinese search engine from China, I wrote two posts on my personal blog: Chinese netizens’ open letter to the Chinese government and Google and “One Google, One World; One China, No Google”

Today, the Congressional Executive China Commission conducted a hearing titled Google and Internet Control in China: A Nexus Between Human Rights and Trade? They had originally invited me to testify in a similarly titled hearing, “China, the Internet and Google,” which was postponed and rescheduled twice: the first attempt was foiled by the Great Snowcalypse; the second attempt scheduled for March 1st was postponed again at the last minute for some reason that isn’t entirely clear. Meanwhile I had already gone and written my testimony, improved by very helpful input from the CITP community. Unfortunately, when they rescheduled the hearing they said I was no longer invited. They wanted the hearing to have different witnesses from recent related hearings in both the House and Senate. Given that I appeared in both hearings it seems reasonable that they’d want to hear from some other people.

Given the effort that went into my testimony, however, and since it drills down in a lot more detail on China than my testimony for the other hearings, I think there is some value in my sharing it with the world. Here is the PDF and here it is as a web page. Some highlights:

From the introduction:

China is pioneering a new kind of Internet-age authoritarianism. It is demonstrating how a non-democratic government can stay in power while simultaneously expanding domestic Internet and mobile phone use.  In China today there is a lot more give-and-take between government and citizens than in the pre-Internet age, and this helps bolster the regime’s legitimacy with many Chinese Internet users who feel that they have a new channel for public discourse. Yet on the
other hand, as this Commission’s 2009 Annual Report clearly outlined, Communist Party control over the bureaucracy and courts has strengthened over the past
decade, while the regime’s institutional commitments to protect the universal rights and freedoms of all its citizens have weakened.

Google’s public complaint about Chinese cyber-attacks and censorship occurred against this backdrop.  It reflects a recognition that China’s status quo – at least when it comes to censorship, regulation,and manipulation of the Internet – is unlikely to improve any time soon, and
may in fact continue to get worse.

Overview of Chinese Internet controls

Chinese government attempts to control online speech began in the late 1990’s with a focus on the filtering or “blocking” of Internet content. Today, the government deploys an expanding repertoire of tactics.

In other words, filtering is just one of many ways that the Chinese government limits and controls speech on the Internet. The full text then gives descriptions and explanations of the other tactics, but in brief they include:

  • deletion or removal of content at the source
  • device and local-level controls
  • domain name controls
  • localized disconnection or restriction
  • self-censorship due to surveillance
  • cyber-attacks
  • government “astro-turfing” and “outreach”
  • targeted police intimidation

I then describe a number of efforts by Chinese netizens to push back against these tactics, which include (see the full text for further explanation):

  • informal anti-censorship support networks
  • distributed web-hosting assistance networks
  • crowdsourced “opposition research”
  • preservation and redistribution of censored content
  • humorous “viral” protests
  • public persuasion efforts

I end with a set of recommendations. Once again, see the full text for explanations, but here is the basic list:

  • anti-censorship tools – including outreach and education in their use
  • anonymity and security tools – to help people better defend against cyber-attacks, spyware, and surveillance
  • platforms and networks for the capture, storage, and redistribution of content that gets deleted from domestic social networking and publishing services
  • support for “opposition research” – remember the Chinese netizens who deconstructed Green Dam?
  • corporate responsibility – see Global Network Initiative, but also appropriate legislation if American and other Western Internet companies fail to accept the idea that they have some obligations as far as free expression and privacy are concerned
  • private right of action – so that Chinese victims can sue U.S. companies in U.S. courts
  • incentives for innovation by the private sector that helps Chinese Internet users access blocked sites as well as protect themselves from attacks and surveillance.

My conclusion:

Many of China’s 384 million Internet users are engaged in passionate debates about their communities’ problems, public policy concerns, and their nation’s future. Unfortunately these public discussions are skewed, blinkered, and manipulated – thanks to political censorship and surveillance. The Chinese people are proud of their nation’s achievements and generally reject critiques by outsiders even if they agree with some of them. A democratic alternative to China’s Internet-age authoritarianism will only be viable if it is conceived and built by the Chinese people from within. In helping Chinese “netizens” conduct an un-manipulated and un-censored discourse about their future, the United States will not imposing its will on the Chinese people, but rather helping the Chinese people to take ownership over their own future.

CITP is a Google Summer of Code 2010 Mentoring Organization

The Google Summer of Code program provides student stipends for summer work on open source projects. CITP is thrilled to have been chosen as a mentoring organization for 2010, meaning that students will be working on some CITP projects this summer. We think that these projects are very interesting, and potential participants now have the opportunity to propose their ideas for what they’d like to work on. Applications accepted from March 29 to April 9.

You can browse our list of project ideas, read our overall description, and apply here.