If you do something bad and covert it up, it's a bad secret because it results in bad things and the politicians involved do not want to be associated with the result. Such a thing musn't be a secret. It's wrong to cover up a bad thing because it's hiding something that could hurt you and others in the future. If the government's job should be to keep the society's justice then it's absolutely necessary not to hide bad things otherwise they're lying. So it's not the government's place to hide bad secrets.
Good things don't need to be lauded (humility) and they don't need to be covered up either. Since it's not going to result in a bad thing and hurt the society then it doesn't have to revealed unless you would like to use the good thing. For example, if private stuff in his life is actually private and not hurting anyone else, then he should be allowed to keep the secret if he decides to because it's his own life.
If there is this principle to tell good and bad in people's activities then it solves his question.