keep in ignorance
keep (someone or oneself) in ignorance
To ensure that someone or oneself remains oblivious to, ignorant of, or misled about the truth. Often followed by "of" or "about" something. The dictatorship has kept its citizens in ignorance of the outside world as a way of keeping them under control. The news just depresses me these days, so I prefer to simply keep myself in ignorance. The boss kept the entire team in ignorance about the company's mounting financial troubles.
keep someone in ignorance (about someone or something)
to prevent someone from learning specific information about someone or something. I think we had better keep them all in ignorance about the money for a while. I don't know about her. I have kept my self in ignorance on purpose.