LaCie Private-Public software is being discontinued for both Windows and macOS.
macOS:
macOS 10.13.4 announced that macOS would be discontinuing support for 32-bit applications in the future, for more details see this Apple KBA. Private-Public is a 32-bit application and development has been discontinued. When Private-Public is launched it will show this message:
It is recommended that a replacement is found for Private-Public as soon as possible since macOS 10.14 (Mojave) will be the last version of macOS to support 32 bit applications.
Windows:
Since macOS development has stopped it was determined that development for Windows would also be discontinued at this time.
IMPORTANT:
There are alternatives available with varying capabilities, a web search should provide a variety of alternatives. These 3rd party alternatives are not endorsed by LaCie.
