CompTIA Security+ Question L-71

A company is preparing to decommission an offline, non-networked root certificate server. Before sending the server’s drives to be destroyed by a contracted company, the Chief Security Officer (CSO) wants to be certain that the data will not be accessed. Which of the following, if implemented, would BEST reassure the CSO? (Select TWO).

A. Disk hashing procedures
B. Full disk encryption
C. Data retention policies
D. Disk wiping procedures
E. Removable media encryption

Answer: B,D

Explanation:
B: Full disk encryption is when the entire volume is encrypted; the data is not accessible to someone who might boot another operating system in an attempt to bypass the computer’s security. Full disk encryption is sometimes referred to as hard drive encryption.

D: Disk wiping is the process of overwriting data on the repeatedly, or using a magnet to alter the magnetic structure of the disks. This renders the data unreadable.

CompTIA Security+ Question L-51

A certificate authority takes which of the following actions in PKI?

A. Signs and verifies all infrastructure messages
B. Issues and signs all private keys
C. Publishes key escrow lists to CRLs
D. Issues and signs all root certificates

Answer: D

Explanation:
A certificate authority can issue multiple certificates in the form of a tree structure. A root certificate is part of a public key infrastructure (PKI) scheme. The most common commercial variety is based on the ITU-T X.509 standard, which normally includes a digital signature from a certificate authority (CA). Note: In cryptography and computer security, a root certificate is an unsigned public key certificate (also called self-signed certificate) that identifies the Root Certificate Authority (CA).

CompTIA Security+ Question K-31

A CA is compromised and attacks start distributing maliciously signed software updates. Which of the following can be used to warn users about the malicious activity?

A. Key escrow
B. Private key verification
C. Public key verification
D. Certificate revocation list

Answer: D

Explanation:
If we put the root certificate of the comprised CA in the CRL, users will know that this CA (and the certificates that it has issued) no longer can be trusted. The CRL (Certificate revocation list) is exactly what its name implies: a list of subscribers paired with digital certificate status. The list enumerates revoked certificates along with the reason(s) for revocation. The dates of certificate issue, and the entities that issued them, are also included. In addition, each list contains a proposed date for the next release.

CompTIA Security+ Question E-51

The recovery agent is used to recover the:

A. Root certificate
B. Key in escrow
C. Public key
D. Private key

Answer: D

Explanation:
A key recovery agent is an entity that has the ability to recover a private key, key components, or plaintext messages as needed. Using the recovered key the recovery agent can decrypt encrypted data.

CompTIA Security+ Question D-19

An administrator has successfully implemented SSL on srv4.comptia.com using wildcard certificate *.comptia.com, and now wishes to implement SSL on srv5.comptia.com. Which of the following files should be copied from srv4 to accomplish this?

A. certificate, private key, and intermediate certificate chain
B. certificate, intermediate certificate chain, and root certificate
C. certificate, root certificate, and certificate signing request
D. certificate, public key, and certificate signing request

Answer: A

Explanation:
a wildcard certificate is a public key certificate which can be used with multiple subdomains of a domain. In public-key cryptography, the receiver has a private key known only to them; a public key corresponds to it, which they make known to others. The public key can be sent to all other parties; the private key is never divulged. A symmetric algorithm requires that receivers of the message use the same private key. Thus you should copy the certificate, the private key and the intermediate certificate chain from srv4 to srv5.

CompTIA Security+ Question B-84

A network administrator is looking for a way to automatically update company browsers so they import a list of root certificates from an online source. This online source will then be responsible for tracking which certificates are to be trusted or not trusted. Which of the following BEST describes the service that should be implemented to meet these requirements?

A. Trust model
B. Key escrow
C. OCSP
D. PKI

Answer: A

Explanation:
In this scenario we can put a CA in the local network and use an online CA as root CA in a hierarchical trust model. A trust Model is collection of rules that informs application on how to decide the legitimacy of a Digital Certificate. In a hierarchical trust model, also known as a tree, a root CA at the top provides all of the information. The intermediate CAs are next in the hierarchy, and they trust only information provided by the root CA. The root CA also trusts intermediate CAs that are in their level in the hierarchy and none that aren’t. This arrangement allows a high level of control at all levels of the hierarchical tree.