Passwords as access security

Relying on a password to secure access to a system does not provide enough security in today’s complex world. The Office of Personnel Management learned this the hard way in 2015. Since OPM was hacked and it was learned that the attackers compromised their system administrator accounts that were protected only with passwords, the Federal government has required the use of multifactor authentication for privileged accounts. Describe the three factors that can be used in authentication and give at least two examples for each.