Asymmetric Cryptography and Key Algorithms BDC Practice Questions (Page 9)

Questions 41–44

1. 41application · medium

   A blockchain platform needs to support both transaction signing and encryption of small payloads. Which algorithm is commonly used for both?

   • ADiffie-Hellman
   • BSHA-256
   • CRSA
   • DECDSA
   Reveal Solution Discussion Select an answer first
2. 42application · medium

   A blockchain node receives a transaction with a signature. To validate the transaction, the node must verify the signature. What is the first step in this process?

   • ADecrypt the signature with the sender's private key.
   • BHash the signature with the transaction data.
   • CSend the transaction to the network for approval.
   • DObtain the sender's public key from the transaction or address.
   Reveal Solution Discussion Select an answer first
4. 43foundation · easy

   In a digital signature scheme, what does the signer use to create the signature?

   • AThe recipient's public key
   • BA shared symmetric key
   • CThe signer's private key
   • DThe recipient's private key
   Reveal Solution Discussion Select an answer first
5. 44application · medium

   An organization runs a permissioned blockchain where each participant has a certificate containing a public key. A participant's private key is suspected to have been compromised. The organization needs to prevent the compromised key from being used for future transaction signing while preserving the integrity of previously signed transactions. What is the correct course of action?

   • AUse the compromised private key to sign a revocation transaction, then discard it.
   • BChange the participant's private key in the certificate without re-issuing the certificate.
   • CRevoke the certificate and issue a new key pair to the participant, while keeping the old public key available for verifying past signatures.
   • DDelete the participant's public key from the network so that no one can verify their signatures.
   Reveal Solution Discussion Select an answer first