Attack Surfaces in Blockchain Ecosystems BDC Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A blockchain startup's CFO receives an urgent email that appears to be from the CEO, asking her to transfer 50 ETH to a 'vendor wallet' for a time-sensitive acquisition. The email domain is similar but not identical to the company's domain. The CFO has never seen this wallet address before. What is the most appropriate immediate action?

   • ACheck the company's blockchain explorer to see if the wallet address has any transaction history before transferring.
   • BReply to the email asking for confirmation of the wallet address.
   • CTransfer the ETH immediately because the CEO's request is urgent and delaying could lose the acquisition.
   • DVerify the request through a second communication channel, such as a phone call to the CEO using a known number, before any transfer.
   Reveal Solution Discussion Select an answer first
2. 2application · medium

   A blockchain network is experiencing a large number of fake nodes joining the network, each with a different identity. These nodes are used to influence the network's peer selection and potentially isolate honest nodes. Which attack is this, and what is a common defense?

   • ADDoS attack; use rate limiting on incoming connections.
   • BSybil attack; require proof-of-work or proof-of-stake for node identities.
   • C51% attack; increase the block size.
   • DEclipse attack; use a diverse set of peers.
   Reveal Solution Discussion Select an answer first
4. 3expert · hard

   A decentralized autonomous organization (DAO) uses a token-based voting system where each token equals one vote. A wealthy investor acquires 35% of the total token supply and proposes a change that would redirect treasury funds to a project they control. The proposal is controversial, and many small token holders are apathetic and do not vote. What is the most effective way to mitigate this governance attack?

   • AIncrease the voting power of small token holders by giving them bonus votes.
   • BImplement a voting delay and a quorum requirement that ensures a minimum percentage of tokens must participate for the proposal to pass.
   • CRequire a two-thirds majority of all tokens to pass any proposal, regardless of voter turnout.
   • DAllow the DAO's core team to veto any proposal that they deem harmful.
   Reveal Solution Discussion Select an answer first
5. 4foundation · easy

   Which of the following is a common threat to wallet and private key management?

   • AThe wallet software having a user-friendly interface
   • BThe blockchain network being temporarily offline
   • CPhishing attacks that trick users into entering their private keys on a fake website
   • DThe price of the cryptocurrency dropping significantly
   Reveal Solution Discussion Select an answer first
6. 5foundation · easy

   Which of the following is a main component of the attack surface in a blockchain ecosystem?

   • AThe consensus algorithm's configuration parameters
   • BThe marketing strategy of the blockchain project
   • CThe color scheme used in the official wallet application
   • DThe physical location of the blockchain's headquarters
   Reveal Solution Discussion Select an answer first