It seems not a day passes without news on leakage of confidential information from governmental and other entities onto the Internet. The types of information leaked are vast and the content is critical — Self-Defense Forces-related documents, quake-resistance data for nuclear-power plants, access codes for restricted areas at airports, police investigation records, the names of sex-crime victims, personal information on as many as 10,000 convicts, data on hospital patients, information on customers of private firms, and so forth.

The main culprit is the peer-to-peer file-sharing software Winny. To be exact, the real culprits are a virus that infects Winny and people who are careless when using their Winny-enabled privately owned computer for official work.

The leaks have been occurring for a long time but the government became serious about the Winny problem only after it was found in late February that the Maritime-Self Defense Force-related data had leaked from a private-use computer of a non-com communication officer aboard the destroyer Asayuki, deployed at Sasebo base in Nagasaki Prefecture. The leak included the telephone and fax numbers of more than 100 MSDF ships, a table of random numbers to read special reports on combat exercises and a roster of MSDF members.

To prevent virus infections, Chief Cabinet Secretary Shinzo Abe has issued a call on the public not to use Winny. But it is not certain if all the Winny users, said to number more than 300,000, will heed his call. And there may be viruses that attack other software. Winny, which was made public on the Internet in 2002, makes it possible to exchange documents, music, images and other files among an unspecified large number of computer users. Users designate files that can be copied by other users. The latter search for such files on the Internet and can download them free of charge. Files are exchanged not through a server but through a computer network. But if a virus-infected file is downloaded into a computer, files inside the computer not designated for copying are instantly leaked onto the Internet. An estimated 1.27 million people were using Winny and other file-sharing software as of January 2005. Copyright violations are suspected in a majority of computer files obtained this way.

The spate of leaks has shed light on the lack of awareness about the danger involved in the use of Winny and general slackness in the use of computers — not only on the part of home computer users but also on the part of organizations like the SDF and police. Leaks occur because some people copy data from master files at their work places and put them into their privately-owned computers. The non-com officer aboard the destroyer Asayuki, for example, copied data inside the ship and fed them into his Winny-enabled home computer. This was a clear violation of work rules. That non-com officer’s home computer had already been infected by a virus from a downloaded file, which caused Winny to leak the ship’s information.

The National Police Agency has banned police officers’ use of Winny, unauthorized connections to the Internet and the unauthorized removal of office computers, and also decided to encode police information. The Defense Agency has announced purchase of about 56,000 computers to prevent leakage. But surveys show that they were not well-guarded. As of April 2005, the police were allowing about 104,000 privately-owned computers to be used for official duties, against some 92,000 office-issue computers. SDF members and Defense Agency officials were using about 120,000 privately-owned computers to compile data either at home or at the office, with 80 of them containing Winny.

The leak incidents suggest the necessity to consider banning, in principle, use of private computers for work and laying down strict rules concerning handling of computer data, including use of data-storage mediums such as flash drives and portable hard drives. At the individual level, it has become all the more important to install and update anti-virus software, not only to protect their own computers but also to prevent damage to other users’ computers since viruses can spread from computer to computer through the Internet. One simple rule is that one should not open an e-mail whose origin is unknown or download files from unfamiliar sources.

One irony about Winny is that police officers used computers incorporating the software, causing information leakage, even after the Kyoto prefectural police arrested the Winny designer in April 2004 on suspicion of aiding copyright violations through his invention of the software and his subsequent improvements of it. He says he can redesign Winny to prevent virus-related leakages or to erase leaked files but he will not do so because the act would constitute an improvement of the software, for which he has already been arrested. This episode shows that the revision of present laws or enactment of new laws can contribute to making the Internet safer. The bottom line is everyone should be aware that the Net is full of dangers.

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