What is the ruling on working in banks and companies that deal with usury, and do Islamic banks today differ from usurious banks?

Working in usurious banks is forbidden in all their departments, even if the worker is a guard, as is working as an accountant in companies and factories that deal with usury. University education is not an excuse to engage in forbidden work, and a Muslim must be keen on earning a lawful living. There are permissible fields of work for university degrees, such as Islamic satellite channels, Islamic banks, companies, factories, and institutions owned by righteous people, and currency exchange shops. One must search for permissible work without being distracted by appearances, for lawful earning is better and more blessed, even if it comes from simple professions. The Prophet, peace and blessings be upon him, encouraged eating from the labor of one's hands.