Concept
is a peer-to-peer (P2P) application from Japan designed for use with Microsoft Windows. It was launched in 2006. Its author is known by the pseudonym Kaichō. Perfect Dark was developed with the intention for it to be the successor to both Winny and Share software. While Japan's Association for Copyright of Computer Software reported that in January 2014, the number of nodes connected on Perfect Dark (24000) was less than on Share (44000), but more than on Winny (12000), Netagent in 2018 reported Winny being the largest with 50 000 nodes followed by Perfect Dark with 30 000 nodes followed by Share with 10 000. Netagent asserts that the number of nodes on Perfect Dark have fallen since 2015 while the numbers of Winny hold steady. Netagent reports that users of Perfect Dark are most likely to share books/manga. As of version 1.02 (2008), code-named "Stand Alone Complex", there is support for the program to run in English, an option that can be selected when the program is installed. Perfect Dark is still being actively developed. The author does not ask that the program's users at this point become dedicated "users" of the software. Instead, the author asks them to participate in the test phase. Through this test phase, the author hopes for bug reports and discussion that will help shape Perfect Dark into a better program. The author implements an architecture called DKT+DHT+DU in the design of the network. These three parts compose the entire network. "DKT" stands for Distributed Keyword Table. "DHT" for Distributed Hash Table. "DU" for distributed Unity. "DKT" is mainly for providing effective file searching while "DHT" and "DU" is used for effective file sharing and enhancing anonymity. Perfect Dark has higher bandwidth and hard drive space requirements than its predecessors Winny and Share. The minimum upload speed is 100 kbit/s. Perfect Dark requires more network bandwidth and hard disk space than Winny or Share, forcing a fairer load on all users.
