Winny

Winny (also known as WinNY) is a Japanese peer-to-peer (P2P) file-sharing program that claims to be loosely inspired by the design principles behind the Freenet network and that also claimed to keep user identities untraceable. While Freenet was implemented in Java, Winny was implemented as a Windows C++ application.

The software takes its name from WinMX, where the M and the X are raised one letter in the Latin alphabet, to N and Y. As of September 2003, there were 250,000 users of the program according to the Tokyo-based Association of Copyright for Computer Software. According to P2Pnet, it was the most popular file-sharing program in Japan, with WinMX in second place.

The software was developed by Isamu Kaneko, who is a research assistant in graduate course of computer engineering at the University of Tokyo in Japan. He was also once a researcher at the Japan Atomic Energy Research Institute. Kaneko originally anonymously announced his intent of developing the software on the Download Software board (which was a board filled with copyright infringers) of the popular 2channel (2ch for short) Japanese bulletin board site. Since 2ch users often refer to anonymous users by their post numbers, Kaneko came to be known as "Mr. 47" ("47-Shi", or 47氏 in Japanese), or just "47".

On November 28, 2003, two Japanese users of Winny, Yoshihiro Inoue¹, a 41 year-old self-employed businessman from Takasaki, Gunma Prefecture and an unemployed 19-year-old from Matsuyama, were arrested by the Kyoto Prefectural Police. They were accused of sharing copyrighted material via Winny and admitted to their crimes. Shortly following the two users' arrests, Kaneko also had his home searched and had the source code of Winny confiscated by the Kyoto Police.

On May 10, 2004, Kaneko was arrested for suspected conspiracy to commit copyright violation by the High-tech Crime Taskforce of the Kyoto Prefectural Police.

Kaneko's arrest caused an uproar in communities on the Internet, including 2ch, citing it as an unjust arrest. A website set up to raise money for the defense of Kaneko has raised over 11 million yen (about 97,000 US$ on May 23, 2004) within two weeks.

Kaneko was released on bail on June 1, 2004. The court hearings started in September 2004 at Kyoto district court.

After Winny's development was stopped, Share was started by an anonymous Japanese engineer to pick up where Winny left off.

Winny's Anonymity

At the time of the two users' arrests, the Kyoto Police claimed to have "analyzed Winny's anonymity features" to track the users down, but did not disclose the exact method used. It later turns out, as the details of the method used was disclosed at Kaneko's first day of trial, that this statement was not entirely accurate — It was areas where Winny did not provide anonymity that the Police used to track users down.

After failing to crack Winny's encrypted communications used in its file sharing feature, the Kyoto Police switched to a different method, namely tracking users via Winny's integrated forum feature. Unlike its file sharing feature, the forum feature of Winny provided anonymity for users who accessed message threads, but not for creators of threads. Users accessing threads were able to determine the IP address of the originator of the thread.

The Kyoto Police first looked for a thread where its originator was posting the file names of copyrighted material he was sharing, and recorded his IP address. They then configured their firewall to only allow connections to them from the thread owner's IP address. Finally, they confirmed that they could indeed download the copyrighted file from the user who stated (on his thread) that he was sharing it.

Debate of Winny's Purpose

Critics of Kaneko have stated that the main purpose of Winny is to violate copyright law, unlike Freenet, another peer-to-peer system that Winny is often compared to, which claims to protect freedom of speech. These critics also claim that 2ch's Download Software board, where the software was first announced, is a haven for copyright violators, and that Kaneko himself had said that the aim of development of Winny is to push the tide towards a world filled with copyright infringement, quoting several posts from 2ch.

In one of the posts in 2ch Download Software board, "47" had pointed out that '... beta 8.1 [of Winny] has a security hole and is not anonymous. Don't exchange illegal files [with it].' ². Critics claim that this is one evidence of Kaneko's malicious intent, as that "47" was advising users not to share copyrighted material on beta 8.1 because it was not anonymous and infringing users could be traced.

Others have said that Kaneko's action shouldn't constitute a crime, since he didn't infringe copyright himself, but that he just created software that could be used for that purpose. They also state that the claims of Kaneko's intent by his critics are unprovable (some go as to it being outright false), as Kaneko's noted statements are too vague to be interpreted as having the intent claimed by critics. According to the Free Kaneko website, he warned not to share illegal material using the software.

Notes

1. Earlier versions of this article had stated the name of the 41-year-old man as "Katsuhiko Kimoto". The Police and the media initially used this name, as the man used it to identify himself, and the claim could not be verified. Police later found out that the name was an alias. Inoue himself claims to have been using the Kimoto name regularly.
2. Quote was translated from the original Japanese, which can be found at http://winny.info/2ch/main/1021057195.html#526.
3. The final version of Winny released by Kaneko himself is 2.0b7.1.
4. b7.26 is the version to which a hacker called lark hexedited in some new features, it is widely unused.

Further reading

• Kaneko Isamu (2005). The Technology of Winny, 201, ASCII. ISBN 4-756-14548-5. (Japanese)