Blockchain Wallets and Key Management Techniques BBLC Practice Questions (Page 2)

Questions 6–10

1. 6expert · hard

   A user receives a phone call from someone claiming to be from the wallet provider's support team. The caller says there is a security issue and asks the user to read their recovery phrase over the phone to verify their identity. The user is concerned about social engineering. What is the most appropriate action?

   • AHang up and contact the wallet provider using the official phone number from their website
   • BAsk the caller to verify their identity by providing the first few words of the recovery phrase
   • CCall the caller back at the number they provided to confirm the request
   • DProvide the recovery phrase to the caller to resolve the security issue
   Reveal Solution Discussion Select an answer first
2. 7foundation · easy

   What is the recommended first step in a wallet backup and recovery procedure?

   • ATake a screenshot of the private key and save it to the cloud
   • BMemorize the private key and rely on memory
   • CEmail the private key to yourself for safekeeping
   • DWrite down the mnemonic phrase and store it in a secure offline location
   Reveal Solution Discussion Select an answer first
4. 8expert · hard

   A user's hardware wallet was recently used on a compromised computer. The user suspects that a keylogger may have captured the PIN, but the recovery phrase was never entered on the computer. The user wants to ensure that the funds are safe. What is the most appropriate action?

   • AChange the PIN on the hardware wallet and continue using it
   • BTransfer the funds to a new wallet created on a different hardware wallet, and reset the compromised device
   • CContact the hardware wallet manufacturer to have the device's firmware updated
   • DEnter the recovery phrase into a software wallet on a clean computer to check the balance
   Reveal Solution Discussion Select an answer first
5. 9application · medium

   A user receives an email that appears to be from a popular wallet provider, warning that their account has been locked and asking them to click a link to verify their recovery phrase. The user is suspicious. What is the most appropriate action for the user to take?

   • ADo not click the link, and report the email as phishing to the wallet provider's official support channel
   • BForward the email to a friend who is also a cryptocurrency user for advice
   • CClick the link and enter the recovery phrase to verify the account
   • DReply to the email with the recovery phrase to prove ownership
   Reveal Solution Discussion Select an answer first
6. 10application · medium

   A developer is building a new cryptocurrency wallet application. The developer wants to ensure that each user's private key is generated with sufficient entropy and that the user can recover the wallet on a new device without needing to back up every individual private key. Which approach should the developer implement?

   • AGenerate a mnemonic phrase from a dictionary and use it directly as the private key
   • BGenerate a random 256-bit seed using a cryptographically secure random number generator and derive all keys from it using a hierarchical deterministic (HD) wallet structure
   • CUse a fixed master private key for all users and derive child keys with a simple counter
   • DGenerate each private key independently using a pseudorandom number generator seeded with the current timestamp
   Reveal Solution Discussion Select an answer first