ZK-SNARK vs ZK-STARK
Two types of zero-knowledge proof systems — differences in security and efficiency.
Zero-knowledge proof systems enable proving a claim without revealing information — two dominant implementations are ZK-SNARK and ZK-STARK.
ZK-SNARK (Succinct Non-interactive ARgument of Knowledge):
•Short proof size (< 1KB)
•Fast verification
•Requires trusted setup (potential backdoor)
•Groth16 most commonly used SNARK
Where used:
•Zcash — private transactions
•zkSync Era
•Polygon Hermez
•Tornado Cash (mixer)
ZK-STARK (Scalable Transparent ARgument of Knowledge):
•No trusted setup (transparent cryptography)
•Quantum resistant (post-quantum security)
•Larger proof size than SNARK
•Faster to generate (proving)
Where used:
•StarkEx / Starknet
•dYdX v3 (StarkEx)
•ImmutableX (NFT gaming)
Plonk and Recursive proofs:
•PLONK — new SNARK standard without per-circuit trusted setup
•Recursive proof: proof that verifies another proof
•Enables: batching thousands of transactions into one proof
Practical applications:
•L2 rollup verification on L1
•Privacy coins
•Identity proof (zkKYC)
•Machine learning inference proof
Trend:
•"ZK everything" — more applications beyond finance
•EVM equivalent ZK (Polygon, zkSync, Scroll)
•Proof generation hardware (FPGA/ASIC for ZK)