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| China-Japan-Koreas |
| How the Chinese firewall filters the interne... |
| 2008-11-22 |
| The researchers took the Chinese version of Wikipedia, extracted individual words and used a mathematical technique called latent semantic analysis to work out the relationships between different words. If one of the words was censored within China, they could look up which other closely related words are likely to be blocked as well. Examples of words tested by the researchers and found to be banned included references to the Falun Gong movement and the protest movements of 1989; Nazi Germany and other historical events; and general concepts related to democracy and political protest. "Imagine you want to remove the history of the Wounded Knee massacre from the Library of Congress," Crandall said. "You could remove 'Bury My Heart at Wounded Knee' and a few other selected books, or you could remove every book in the entire library that contains the word 'massacre.'" By analogy, Chinese Internet censorship based on keyword filtering is the equivalent of the latter — and indeed, the keyword "massacre" (in Chinese) is on the blacklist. Because it filters ideas rather than specific Web sites, keyword filtering stops people from using proxy servers or "mirror" Web sites to evade censorship. But because it is not completely effective all the time, it probably acts partly by encouraging self-censorship, Barr said. When users within China see that certain words, ideas and concepts are blocked most of the time, they might assume that they should avoid those topics. When the Chinese system detects a banned word in data traveling across the network, it sends a series of three "reset" commands to both the source and the destination. These "resets" effectively break the connection. |
| Posted by:3dc |
| #1 Two words: SSH tunnel. |
| Posted by: Rupert Slort1496 2008-11-22 16:14 |