Is it permissible to obtain a government financial bond (Western) for your children and deposit it in a bank until they reach 18 years of age, in exchange for profits?

If the aforementioned document is a gift from the state or an interest-free loan, then there is no impediment to benefiting from it. However, placing it in an interest-based bank to gain interest is not permissible because it constitutes explicit forbidden usury (riba).