1,168 keywords Skype uses to censor, monitor its Chinese users

1,168 keywords Skype uses to censor, monitor its Chinese users

Summary: One U.S. researcher has deconstructed a constantly updated file in the China-only version of Skype that contains a list of more than 1,100 words used to censor and monitor its users.


It's no secret that the Chinese government is spying on its own citizens, and censoring what they see and access online. But for major players in the technology industry, such as Microsoft, a foothold in the lucrative Chinese market is worth bowing down to certain ethical considerations that would not ordinarily pass in the Western world.

One U.S. student has shown that, amid rumors that Skype is not as secure or as private as it is believed to be, the Chinese authorities are able to snoop and censor text-based conversations for active censorship and surveillance purposes. 

A little back story.

In order to expand to the Chinese market, Microsoft developed a version of Skype, which the Redmond, Washington-based company bought in 2011 for $8.5 billion, with TOM Online, a China-based mobile Internet company. In doing so, it's left a trail of controversy in the eyes of privacy and civil liberties groups, not limited to the Electronic Frontier Foundation (EFF), for pandering to the requirements of the 'oppressive' Chinese government.

The trouble for Microsoft is that in China you have to play by its rules. Exactly how much data is handed to or acquired by the Chinese government from Skype users, however, is not yet known. The EFF and others signed an open letter in January demanding that Microsoft release a transparency report, detailing how the company deals with requests for user data in China and around the world.

The EFF, among others, wanted Microsoft to provide details on the "current operational relationship between Skype with TOM Online in China and other third-party licensed users of Skype technology" is, in order to understand the surveillance and censorship capabilities that users may be subject to.

While Microsoft-owned Skype admits that the China-only version offered by its joint-venture partner contains a chat filter "in accordance with local law," and that TOM Online is the majority stakeholder in the arrangement.

Microsoft remained quiet on the matter, and did not comment at the time. 

With a sense of hypocricy, Microsoft is a founding member of the Global Network Initiative, a coalition of companies promoting corporate responsibility in online freedom of speech and expression.

Now, 27-year-old University of New Mexico student Jeffrey Knockel has deconstructed some of Skype's code and revealed a list of words that the Chinese government could use to spy on its own citizens, in an interview with Bloomberg.

He says on his Web site that: "These lists are used for both censorship and surveillance unless otherwise noted."

His work focused on the text-based communications between TOM-Skype users, and does not relate to the Internet calling (VoIP) service that the service is primarily used for.

But the worrying factor here is that Knockel discovered that TOM-Skype contains a surveillance feature, that when an "offending phrase" is detected a copy of that word is sent to a TOM-Skype server with the account's username, date and time stamp, and whether or not the message was received by the recipient. 

While that data may or may not be shared directly with the Chinese government, the country's law enforcement and intelligence services have the legal right to 'subpoena' that data at will and bring charges against citizens—in many cases without a warrant. 

Some of these words include (more can be found here, updated daily). In just a sample, you can see that some of these words relate to past events—much of which are censored by Internet providers under mandate by Chinese law to citizens in the country—but also show the overreaching steps by the ruling party to limit the flow of open information to its people:

  • Sixty-four
  • Campus upheaval
  • Truthfulness
  • Global human era
  • Actor temperature
  • Jiang Zemin died suddenly
  • Anti-Japan
  • Ferrari
  • 22 years ago
  • Democratic Unionist Party
  • Amnesty International
  • Reporters Without Borders
  • Flowers to Google
  • Sex video
  • Sale of fireworks
  • Quebec

While results relating to the Tiananmen Square protests in 1989 are filtered, as well as recent events relating to high profile politicians and suchlike, also in the selection of words are organizations that report on freedom of speech in the country, as well as seemingly random phrases, such as "Ferrari" and "Quebec". 

References to pornography are also actively monitored by the TOM-Skype application and censored at will. 

Knockel discovered during his research that every time he logged in to TOM-Skype, servers based in China would download an ever-updated list of keywords that would hook into the application and monitor his communications. This list of keywords is encrypted but he was eventually able to deconstruct the file into a readable text-based format, albeit in Chinese.

Even those communicating with those outside of China with a version of TOM-Skype are having their communications logged, showing the ability to potentially extra-territorially monitor communications by the Chinese authorities.

From his work, it's now becoming increasingly clear that while Western firms like Microsoft have to comply with Chinese law when operating in the country, there is a significant conflict between U.S. ideals and Chinese oppression of speech. 

Screen Shot 2013-03-08 at 09.24.43
A list of other services that monitor communications in China (Credit: Jeffrey Knockel)

But no doubt, dozens if not hundreds of other Western or U.S.-based firms are also backseating their own morals and principles in order to tap into the lucrative and ever-expanding Chinese populous. 

Knockel, in addition to shedding light on the online censorship and surveillance practices of the Chinese authorites, also received an A+ by his professor for his work.

Topic: China

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  • Real News and the crowd goes quite

    Well I think that M$ and others are greedy and would sell there soul for more market share no matter what, and then say well its not us, its them. They are the majority shareholder. We only designed and left the door open, how where we to know they would go in and ... We are setting ourselves up to fail we the west have been doing this for far to long. Anything for a buck eh.
    • MSN

      I don't disagree, but it is interesting to note that the only instant messenger tested in this work that does not seem to be censored—MSN—is also operated by Microsoft. I'd be inclined to assume that the monitoring and censoring elements of Chinese Skype were implemented before the Microsoft takeover, which would explain this inconsistent handling for two parallel products within the same company.
    • Kudos to Google...

      Kudos to Google for pulling out of China so they don't have to censor search results.
      They probably lost a lot of money and potential market share, but sometimes principles are more important.

      I feel sorry for the Chinese people...
      • Kudos to Google, Kudos to You Guys.

        I am a victim of oppressive censorship in China, I want to tell you that thank you for your concern, Kudos to Google, Kudos to You Guys.
  • Logging in from China

    Censorship is at all levels, and some somewhat arcane. For several months, "Engrade", a program just to store students' marks wouldn't work from within China, but as soon as I stepped into another country, was just find. "Turboschool" was another. Sometimes, attempting to connect directly using https also fails. It is just like Beijing runs a giant proxy server. What the Chinese seem to do is exploit little concessions and add them all together. I find this in education. Can we? "Yes, but..." "Good". The concession might be something to spare a remote school the necessity to do something, not for a Chinese school running a Canadian program in a metropolitan area. The list goes on, so that they get 50% of concessions where no Canadian school would get more than 10% in terms of over-large class sizes, ignoring slabs of the curriculum, etc. It is like specifying a part at 1.000" +/- 0.0025" The Chinese would devote time and energy to making every part 0.976" +/- 0.001" and saying "these are within spec". The alloy content might be specified at 5.0% +/- 0.1% and they will consistently come in at 4.95% +/- 0.05%, and so on. The sad result is that 90% of the original material is used to make rubbish that lasts only 20% of the time compared with making it properly. The Chinese are using all the secrecy provisions of the World Trade Organisation to basically use Chinese state-run corporations to impose Chinese law on the rest of the world. Anyway, I will be dead soon, so what do I care?
  • The Patriot Act

    was the biggest blessing that the 'democratic west' could have given the Chinese to justify any amount of anti-democratic activity. Is it OK to intercept telecommunications without a warrant" "Yes, but..." "Good," say the Chinese, "well you won't object if we do it to our citizens." "Is the death penalty OK?", "Yes, but...", "Well", say the Chinese, "you won't mind if we put a few falun gong to death, will you?" The list goes on. Funny thing, medric, that the only other comments (from me) are from a Westerner studying China!
  • And how many does ZDNet have?

    Have had many comments for here "held for moderation"...and never published, because I used words, or acronyms, that were...

    1) Not profane...or
    2) Did not target anyone personally...or
    3) Used multiple non-controvertial web links...or
    4) Had everyday benign phrases in them.
    • Don't look at me

      Authors do not have any control over the comments whatsoever. Seriously. And our comment system isn't exactly great, sorry.
      • I had an idea of how Microsoft could endear themselves to

        citizens of China especially with regard to the Surface tablet but MSFT's external public relations firm wasn't willing to play ball
      • But could you please relay this to your management

        that it is rude to yell at users for nothing.
        You guys do not even have a link to tech support to which I could send my refused comments.
  • Congratulations to MS...

    ...for its strict adherence to Chinese law. Perhaps it's highly ethical lobbyists can now work toward having Jeffrey Knockel extradited for revealing state secrets.
    John L. Ries
    • MicrosSoft is a business

      It is not their responsibility to "free" oppressed peoples. If you really give a crap about the Chinese peope then you as a person should do everything in your power to fight for them.
      Burger Meister
      • I was being sarastic, of course

        And I have long maintained that the "leave your consicence at the office door" school of business ethics is responsible for most the public mistrust of big business, and thus for the abundance of commercial regulation that's been imposed in the West during the past century. There are a host of other ills resulting from this particular misguided philosophy, but we'll discuss them another time.

        If you run your business like a sociopath, then you deserve to be treated like a sociopath.
        John L. Ries
  • Observing the Laws of the Host Country

    We need to remind ourselves -- per recent Google disclosure -- that the US government made more requests for personal data from Google than all other countries of the world!

    Is Google selling its soul to the government as well? Maybe. But it would be bizarre for Google to ignore government subpoena and other laws here at home. And the same would apply to other countries where Google operates. And the same with Skype and all other companies as well.
    • Perhaps...

      Corporations should be a bit more picky about the countries in which they do business.
      John L. Ries
      • Why

        Because you don't approve? Go peddle your ideology elsewhere
        Burger Meister
        • I don't have to approve

          MS can do business in whatever manner the law allows, and I'm free to express my opinion thereon. And everybody else can take it for what it's worth.

          But there's no way I'd work for MS no matter how much I was paid.
          John L. Ries
          • Re: I Don't...

            At first I thought of agreeing with you, but then I began to wonder...The right pay, and then maybe if the opportunity existed to effect real change then it would be worth it.

  • Google "Gmail FBI NSA backdoor"

    Zack, have you written about Google opening backdoors to allow US government agencies to spy on Americans?
  • haha

    一句话总结 反正天朝很牛逼就是了