Faq/Calc/024/ru

Можно ли открыть защищенный паролем файл Excel в LibreOffice?
Такой файл может быть открыт LibreOffice Calc, если вы знаете пароль от файла.

However examples seem to show that the protection of .xls or .xlsx files sometimes only works within MS Excel. It depends on what type of protection, e.g. some workflow related password protection is not supported.

If the file is stored encrypted with a password then you do need the password to be able to open the file in LibreOffice.