How to gain investors' trust if for security reasons you can't open the information about the project owner to the public?
What organizations are there that provide KYC for project owners?
There's no need for any organization for the owners to provide their KYC. For a simple project, they have a website and they include all of the people behind the team that's working for it.
Gaining trust from investors is hard and that's why I agree to jawhead that there's a need for your project a purpose. If it's the same as the others that have just gained money from the community, you're not getting any trust from anybody.