A Chinese firm, Venus Info Tech Ltd., announced on 11 June that it had received the Ministry of Public Security's first permit to sell a real-time content monitoring and filtering system for SMS. This is outside our usual range of topics, but the company's press release (translated by Babelfish and then polished) strongly suggests that the same technology can be applied to email, IRC and HTTP:
"SMS has quickly become an important channel uniting Internet technology and mobile communications for the dissemination of information in the form of short news messages or notes. The country already has more than 2,800 SMS management units. However, while SMS is very convenient for the user, it also poses significant hidden dangers to information security as every kind of pornographic violence, political rumor, reactionary opinion, cheating trick and illegal advertisement effects social stability. Therefore, a platform for strict and highly effective SMS filters must be established, to guarantee that harmful information is promptly intercepted...."
The press release continues with a technical description of their product, which we must paraphrase because it was quite repetitive: Venus' system uses the Chinese Academy of Science's tests of information content as the basis of its filtering algorithm. There are two main components - management/control centers and filtering engines. The monitoring system gathers bidirectional TCP/IP data and processes a variety of application layer protocols including CMPP, SGIP, SMPP, HTTP, SMTP, etc. It is extremely scalable and does not consume network resources or degrade network performance. The filtering algorithms are rule-based, using keywords or combinations of keywords. Harmful information can be preserved both as plain text and in the original format, along with the source and destination addresses, the time of transmission, etc. Tools are built in for generating reports and warnings for the police, localizing the monitored channel and interrupting the delivery of harmful content, and for retrieving and further processing the recorded data. There are management functions for concurrently selecting users, jurisdictions, SMS content, rules and output diaries. Filtered messages can be preserved for at least 60 days and delivered through encrypted channels to the "correlation department."
While the focus of the company's announcement is on installations inside China, if this product works as claimed, and if its price is as low as Chinese products usually tend to be, exports to other countries may soon follow.