Hashing, Digital Signatures, and Digital Certificates CASENET Practice Questions (Page 2)

Questions 6–10

1. 6foundation · easy

   How can a hash value be used to verify the integrity of a downloaded file?

   • ADecrypt the file using the hash value as a key.
   • BEncrypt the file with the hash value and compare the result to the original.
   • CCompute the hash of the downloaded file and compare it to the published hash value.
   • DCompare the file size to the hash value.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A .NET developer is implementing a document signing feature for a mobile app backend. The documents are small (under 1 KB), and the signing operation runs on a server with limited CPU. The security team requires strong security and fast verification. Which digital signature algorithm is the most appropriate choice?

   • AECDSA with a P-256 curve and SHA-256.
   • BRSA with a 2048-bit key and SHA-256.
   • CHMAC-SHA256 with a shared secret key.
   • DDSA with a 2048-bit key and SHA-256.
   Reveal Solution Discussion Select an answer first
4. 8application · medium

   A .NET developer is implementing a feature that verifies a signed payload received from a partner. The partner signs the payload with their private key. Which .NET class should the developer use to verify the signature?

   • AAesCryptoServiceProvider with CreateDecryptor
   • BSHA256Managed with ComputeHash
   • CRSACryptoServiceProvider with VerifyData
   • DRSACryptoServiceProvider with SignData
   Reveal Solution Discussion Select an answer first
5. 9application · medium

   A .NET developer is designing a password storage system for a new application. The security policy requires that each user's password hash be unique even if two users choose the same password. Which technique must the developer use?

   • AUse SHA-256 without a salt.
   • BUse reversible encryption with a hard-coded key.
   • CUse a per-user random salt and a slow hash algorithm such as PBKDF2.
   • DUse a global static salt for all users.
   Reveal Solution Discussion Select an answer first
6. 10expert · hard

   A company operates a public-facing web application that uses TLS certificates issued by a public CA. The CA announces that it will be compromised, and its root certificate will be distrusted by major browsers. The company's current certificate chain includes the compromised root. What is the most appropriate immediate action?

   • AAdd the compromised root certificate to the server's trust store.
   • BDisable certificate revocation checking to avoid errors.
   • CObtain a new certificate from a different, trusted CA and install it before the distrust takes effect.
   • DWait for the CA to re-issue the same certificate with a new expiration date.
   Reveal Solution Discussion Select an answer first