The checksums below are a simple way for you to double-check the copy of Jaxx you are installing is genuine. You can match the checksum in your instance of Jaxx with the data below.
$ certutil -hashfile Jaxx.Liberty-setup-3.0.0.exe sha256
e6f25ad7d292305f128a82fadcb02d58301b08b6df27f4981ccdfba3c34ef475Download for Windows
$ shasum -a 256 Jaxx.Liberty-3.0.0-i386.AppImage
ac545bacf3603f697d6a526a6a9e67ae33e4916e73f5abd387581d848dbe1c11Download for Linux 32
$ shasum -a 256 Jaxx.Liberty-3.0.0.AppImage
da69e029a437dc3632e46071fbcfc98eb2daa669fdc7aa42d2a3a6b9f6a2048eDownload for Linux 64
*Mac OS X Note: Depending on your system settings, the system might warn you that "Jaxx can't be opened because it comes from an unidentified developer." You can either change your system settings to allow apps from unknown developers in your "Security & Privacy" settings, or simply right click Jaxx → Open (as administrator), which will prompt you with a warning.