Public Key Infrastructure and Digital Signatures CEH Practice Questions (Page 2)

Questions 6–10

1. 6application · medium

   A software vendor distributes a signed update file. A user downloads the file and wants to verify that it was indeed signed by the vendor and has not been altered. Which process should the user follow?

   • AObtain the vendor's public key, compute a hash of the downloaded file, decrypt the digital signature with the public key, and compare the decrypted hash to the computed hash.
   • BCompare the file's size and timestamp to the vendor's published values to ensure authenticity.
   • CEncrypt the downloaded file with the vendor's public key and see if it matches the digital signature.
   • DUse the vendor's private key to decrypt the digital signature and compare it to the file's hash.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   An employee's smart-card certificate is about to expire. The employee is still with the company and needs uninterrupted access to encrypted email. Which process should the certificate authority (CA) perform to ensure the employee can continue using the same identity?

   • ASuspend the certificate until the employee requests a new one.
   • BExtend the certificate's validity period by modifying the existing certificate.
   • CRenew the certificate by issuing a new certificate with a new validity period, possibly reusing the same key pair.
   • DRevoke the expiring certificate and issue a new one with a different key pair.
   Reveal Solution Discussion Select an answer first
4. 8application · medium

   A legal department requires that an employee cannot deny having signed an important contract. The contract is stored electronically. Which mechanism should be used to provide non-repudiation?

   • AAn encrypted copy of the contract using a symmetric key shared with the legal department.
   • BA digital signature created with the employee's private key, which can be verified with the employee's public key.
   • CA timestamp from a trusted time server attached to the contract.
   • DA scanned copy of the employee's handwritten signature on the contract.
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   What is the primary function of a Registration Authority (RA) in a PKI?

   • ATo maintain the certificate revocation list
   • BTo generate the private keys for all users
   • CTo sign certificates on behalf of the CA
   • DTo verify the identity of certificate applicants
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6. 10foundation · easy

   What does a digital signature primarily ensure about the signed message?

   • AThat the message was sent at a specific time
   • BThat the message is stored in a secure location
   • CThat the message is encrypted and unreadable
   • DThat the message has not been altered since signing
   Reveal Solution Discussion Select an answer first