LaCie Private-Public software is being discontinued for both Windows and 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.
Since macOS development has stopped it was determined that development for Windows would also be discontinued at this time.
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.