Crypto Jobs Advanced Topics 3 — Questions and Answers
Question 1: What is the main advantage of an account abstraction (ERC-4337) wallet over a traditional EOA?
- It eliminates all gas fees permanently
- It enables programmable validation like social recovery, gas sponsorship, and batched transactions (Correct answer)
- It stores private keys on-chain for backup
- It requires no signatures to send funds
Correct answer: It enables programmable validation like social recovery, gas sponsorship, and batched transactions
Account abstraction makes wallets smart contracts, enabling features like social recovery, paymasters, and batched operations without changing the base protocol.
Question 2: In tokenomics, what does a 'vesting cliff' refer to?
- A sudden price crash of a token
- A period during which allocated tokens cannot be claimed until a set date, after which they begin unlocking (Correct answer)
- The maximum supply ceiling of a token
- A fee charged when bridging tokens
Correct answer: A period during which allocated tokens cannot be claimed until a set date, after which they begin unlocking
A vesting cliff is an initial lock period before any tokens unlock, used to align team and investor incentives long-term.
Question 3: Which cryptographic primitive underpins most blockchain digital signatures like Bitcoin and Ethereum?
- RSA encryption
- Elliptic Curve Digital Signature Algorithm (ECDSA) (Correct answer)
- AES symmetric encryption
- SHA-256 alone
Correct answer: Elliptic Curve Digital Signature Algorithm (ECDSA)
Bitcoin and Ethereum use ECDSA over the secp256k1 curve to sign transactions and prove key ownership.
Question 4: A cross-chain bridge is exploited for hundreds of millions. What is the typical root cause?
- Bridges always print unlimited tokens by design
- Flawed validation of deposit/withdrawal proofs or compromised multisig keys (Correct answer)
- Excessive transaction speed
- Too many validators participating
Correct answer: Flawed validation of deposit/withdrawal proofs or compromised multisig keys
Most major bridge hacks stem from improper proof verification or compromised signer keys controlling locked funds.
Question 5: What does 'finality' mean in a blockchain consensus context?
- The point at which a transaction is irreversible and cannot be reorganized out (Correct answer)
- The moment a block is first broadcast
- The maximum number of blocks ever produced
- The time it takes to sync a full node
Correct answer: The point at which a transaction is irreversible and cannot be reorganized out
Finality is the guarantee that a confirmed transaction cannot be reversed, which is probabilistic in PoW and often deterministic in BFT-style PoS.
Question 6: Which scenario best illustrates impermanent loss for a liquidity provider?
- The pool is hacked and funds are stolen
- The relative price of pooled assets diverges, leaving the LP with less value than simply holding (Correct answer)
- Gas fees consume the entire deposit
- The token is delisted from an exchange
Correct answer: The relative price of pooled assets diverges, leaving the LP with less value than simply holding
Impermanent loss arises when the price ratio of pooled tokens changes, making the LP position worth less than holding the assets outright.
Question 7: What is the function of a 'paymaster' in account abstraction?
- It mints new native tokens
- It can sponsor or pay gas fees on behalf of users, including in ERC-20 tokens (Correct answer)
- It validates the entire blockchain history
- It sets the network's base fee
Correct answer: It can sponsor or pay gas fees on behalf of users, including in ERC-20 tokens
A paymaster is a contract that can cover users' gas costs, enabling gasless UX or paying fees in tokens other than the native coin.
Crypto Jobs Advanced Topics 3
What is the main advantage of an account abstraction (ERC-4337) wallet over a traditional EOA?