Proof of Stake (PoS) and Derivative Protocols BDC Practice Questions (Page 2)

Questions 6–10

1. 6application · medium

   A blockchain developer is analyzing a Proof of Stake network and is concerned about the 'nothing-at-stake' problem. Which scenario best describes this attack?

   • AValidators lose their entire stake if they propose an invalid block
   • BValidators vote for multiple competing forks because it costs them nothing to do so
   • CValidators are randomly selected to propose blocks, making attacks unpredictable
   • DValidators must pay a large fee to participate in consensus
   Reveal Solution Discussion Select an answer first
2. 7foundation · easy

   In Leased Proof of Stake (LPoS), what does a token holder do to participate in block forging?

   • AThey burn their tokens to gain forging rights
   • BThey vote for a delegate who then forges blocks on their behalf
   • CThey lease their tokens to a forging node, which increases that node's chance of being selected
   • DThey must run a full node and stake their tokens directly
   Reveal Solution Discussion Select an answer first
4. 8application · medium

   A Proof of Stake network is concerned about the 'nothing-at-stake' problem, where validators might vote for multiple competing forks because it costs them nothing. Which mitigation is most directly effective?

   • AIncrease the block size to reduce the number of forks.
   • BUse a longer block interval to give validators more time to choose a fork.
   • CRequire validators to deposit a stake that is slashed if they vote on conflicting forks.
   • DMake the block reward higher so validators are less likely to risk it.
   Reveal Solution Discussion Select an answer first
5. 9foundation · easy

   Which consensus mechanism relies on validators' identity and reputation rather than their cryptocurrency stake?

   • AProof of Burn (PoB)
   • BDelegated Proof of Stake (DPoS)
   • CProof of Importance (PoI)
   • DProof of Authority (PoA)
   Reveal Solution Discussion Select an answer first
6. 10expert · hard

   A developer is comparing PoW and PoS for a new blockchain that must be resistant to censorship and have low energy consumption. The developer is concerned that PoS might be more vulnerable to a 'rich get richer' dynamic. Which design choice can mitigate this concern while still using PoS?

   • ASet a fixed block reward that is the same for all validators.
   • BUse a randomized validator selection algorithm that is weighted by stake but also includes a random component to give smaller validators a chance.
   • CAllow validators to buy more voting power with fiat currency.
   • DUse a pure lottery where every validator has an equal chance regardless of stake.
   Reveal Solution Discussion Select an answer first