Challenger is a encryption software for files and folders. The software can be installed either on a computer or a mobile storage device (USB stick, SD card or CD-ROM). Irrespective whether Challenger is used in the normal multi-user function on the hard drive or as a portable version, in both cases all types of data on any type of storage device can be encrypted. The encrypted data can be securely stored on a network or online (OneDrive, Dropbox). Challenger has been developed for local data protection and communication in closed networks. It excels not only through its secure encryption algorithm but also through its ease of use. The synchronous stream cipher, a development in Germany, delivers a fast encryption. Freeware for private use. Second procedure key is only possible with the full version.