Is secret marriage permissible if the girl goes to the mosque without her parents' knowledge, and there is only one witness?

The validity of marriage requires the presence of a guardian (wali) and two just witnesses, based on the Prophet's (peace be upon him) sayings: "There is no marriage except with a guardian" and "Any woman who marries without the permission of her guardian, her marriage is invalid." If the guardian agrees, then the contract must be renewed in the presence of two just witnesses.