Is it permissible to encrypt some television channels from one's wife and mother to prevent them from watching series and movies, and is the husband sinful for what others watch in his house?

It is not permissible for the husband to decrypt channels or teach his wife the code if he knows she will use it for what is unlawful. The presence of the wife's mother does not make this permissible. The husband must satisfy his wife and her mother with permissible things, apologize to them for watching impermissible series and movies, and convince them that observing the boundaries of Allah is more important. Enabling them to watch unlawful things makes him sinful, as he is the one who brought the device into the home and is responsible for his family.