Yes, your company owns all the inventions you come up, including off-hour work, during your employment with them. And companies are not hesitant to sue to get

Yes, your company owns all the inventions you come up, including off-hour work, during your employment with them. And companies are not hesitant to sue to get your IP. There were cases before and they won. That's why people moved to states like California where protect innovation by individuals. For your current situation, you should keep quiet and keep working on your project. When it's ready, quit your job. Continue to work on it quietly for two months before going public. Good luck.