Finch, a security professional, was instructed to strengthen the security at the entrance.

In the scenario described, Finch implemented a combination of biometric authentication (retina scan) and password authentication (unique six-digit code). Biometric authentication relies on unique physical or behavioral characteristics (such as retina scans) to verify identity, while password authentication requires users to enter a secret code (the six-digit code in this case). Combining these two mechanisms enhances security by requiring both something the user knows (password) and something the user is (biometric) for access. References: EC-Council Certified Security Specialist (E|CSS) documents and study guide12.