Clark, a security team member of an organization, was instructed to secure the premises from unauthorized entries. In this process, Clark implemented security controls that allow employees to enter the office only after scanning their badges or fingerprints. Which of the following security controls has Clark implemented in the above scenario?

Which of the following algorithms uses a sponge construction where message blocks are XORed into the initial bits of the state that the algorithm then invertible permutes?

Ben, a computer user, applied for a digital certificate. A component of PKI verifies Ben's identity using the credentials provided and passes that request on behalf of Ben to grant the digital certificate. Which of the following PKI components verified Ben as being legitimate to receive the certificate? 

Messy, a network defender, was hired to secure an organization's internal network. He deployed an IDS in which the detection process depends on observing and comparing the observed events with the normal behavior and then detecting any deviation from it. Identify the type of IDS employed by Messy in the above scenario.

Jamie wants to send a confidential file to her friend Alice. For this purpose, they installed an application for securely sharing the file. The application employs an encryption algorithm that usesthe same shared secret key for encryption and decryption of data. Identify the type of cryptography employed by the application used by Alice and Jamie for file sharing.