During his talk at Google, Frank Abagnale mentioned the following:
...we will be doing away with passwords in the next 24 months. Passwords will leave the world, there will be no more passwords. There is a new technology called Trusona...it is a company in Scottsdale, Arizona that created a technology for the CIA which we have used now for the last few years....it was the ability for an agent to send data back from the field, such as Afghanistan, on their iPhone and that Langley would know 100% that it is the agent on the other end; to 100% identify the person on the other end of the device. That's a level 4 security, so they basically said "What if we brought this to level 2 security and we did away with passwords..."
What is level 4 security in this context?