Public Key Infrastructure and Digital Signatures CEH Practice Questions (Page 9)

Questions 41–45

1. 41foundation · easy

   Which cryptographic mechanism is essential for providing non-repudiation?

   • ADigital signature
   • BSymmetric encryption
   • CHash function alone
   • DSteganography
   Reveal Solution Discussion Select an answer first
2. 42application · medium

   A company wants to ensure that emails sent between employees are authenticated and tamper-proof. They plan to use digital signatures. Which PKI component is essential for employees to verify each other's signatures?

   • AA public key infrastructure that provides certificates binding each employee's public key to their identity.
   • BA certificate revocation list that employees must check before sending emails.
   • CA shared symmetric key for all employees to encrypt and sign emails.
   • DA hash function that employees use to create a shared secret.
   Reveal Solution Discussion Select an answer first
4. 43expert · hard

   Two organizations, each with its own hierarchical PKI, need to establish trust so that users in one organization can validate certificates issued by the other. They want to avoid creating a single root CA that both must trust. Which trust model best meets this requirement?

   • AHierarchical model, where one organization's root CA becomes the root for both.
   • BBridge CA model, where a third-party CA establishes cross-certification between the two roots.
   • CMesh model, where every CA in both organizations cross-certifies with every other CA.
   • DDirect trust model, where each organization manually installs the other's root certificate in every client's trust store.
   Reveal Solution Discussion Select an answer first
5. 44application · medium

   A developer is implementing a digital signature scheme for a document management system. The system must sign large documents efficiently. Which approach should the developer use to minimize computational overhead while maintaining security?

   • ASign the document multiple times with different keys.
   • BEncrypt the entire document with the signer's private key.
   • CHash the document and sign only the hash value.
   • DUse a symmetric key to encrypt the document and sign the key.
   Reveal Solution Discussion Select an answer first
6. 45application · medium

   A company's web server certificate was compromised when an attacker gained access to the server's private key. The security team needs to inform all clients that the certificate is no longer valid. Which action should the team take to ensure clients stop trusting the certificate?

   • AChange the certificate's serial number in the certificate database.
   • BRevoke the certificate and publish the revocation information via CRL or OCSP.
   • CRenew the certificate with the same key pair.
   • DDelete the certificate from the server and reinstall it later.
   Reveal Solution Discussion Select an answer first