Is it permissible to attribute a child of unknown paternity to his mother in official documents, and to cite Jesus, son of Mary, peace be upon him, as evidence for this?

If "unknown father" refers to the child of adultery, then he is attributed only to his mother. In this, there is no concealment for her (her sin is exposed), but concealing the sins of wrongdoers is not obligatory. If attributing him to his mother is difficult, he can be attributed to a non-real name, a servant of God, such as Abdullah or Abdul Rahman. As for attributing Jesus (peace be upon him) to his mother, it does not serve as proof, because he was born without a father, unlike the child of adultery. The wisdom behind attributing him to his mother is to exonerate her and to show that he is not attributed to a father.