Asymmetric Cryptography and Key Algorithms BDC Practice Questions (Page 2)

Questions 6–10

1. 6application · medium

   A developer is implementing a document verification system on a blockchain. Each document is hashed, and the hash is signed with the author's private key. The signed hash is stored on-chain. To verify a document's authenticity and integrity, what should a verifier do?

   • AHash the author's public key and compare it to the stored hash.
   • BEncrypt the document with the author's public key and compare it to the stored hash.
   • CHash the document, verify the signature on the stored hash using the author's public key, and compare the resulting hash to the document's hash.
   • DDecrypt the stored hash with the author's private key and compare it to the document's hash.
   Reveal Solution Discussion Select an answer first
2. 7application · medium

   A user claims to have sent a transaction on a blockchain. To verify that the transaction was indeed signed by the user's private key, what should a verifier use?

   • AThe user's private key
   • BThe network's consensus key
   • CThe transaction hash only
   • DThe user's public key
   Reveal Solution Discussion Select an answer first
4. 8application · easy

   A healthcare startup is building a system where patients encrypt their medical records before uploading them to a public cloud storage service. Only the patient's designated doctor should be able to read the records. The startup wants to use asymmetric encryption so that the patient does not need to share a secret key with the doctor in advance. Which key should the patient use to encrypt the records?

   • AA shared symmetric key derived from the patient's and doctor's public keys
   • BThe patient's private key
   • CThe patient's own public key
   • DThe doctor's public key
   Reveal Solution Discussion Select an answer first
5. 9expert · hard

   A developer needs to encrypt a large file (e.g., 1 GB) to send to a recipient. The requirement is to use asymmetric cryptography for key exchange but not for the bulk data encryption. Which approach is most appropriate?

   • AEncrypt the file with the recipient's private key.
   • BUse Diffie-Hellman to encrypt the file directly.
   • CGenerate a random symmetric key, encrypt the file with it, and encrypt the symmetric key with the recipient's public key.
   • DEncrypt the entire file with the recipient's public key using RSA.
   Reveal Solution Discussion Select an answer first
6. 10application · medium

   A company is setting up a certificate authority (CA) to issue digital certificates for employees. What is a critical step in the key management process?

   • AUse the same key pair for all employees.
   • BStore private keys in a shared network folder.
   • CPublish the CA's private key to all employees.
   • DSecurely generate and store the CA's private key in an HSM.
   Reveal Solution Discussion Select an answer first