In this track: Trees, roots and proofs
Merkle proof challenge set
Explain leaf encoding, path rules and root authority as one system.
A reliable route needs the correct starting record, directions and authorized destination.
This example hashes UTF-8 A, B, C and D. The displayed hashes are abbreviated, and the tree uses the playground’s sorted-pair convention.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
Challenge one: reproduce a leaf
Hash text A as UTF-8 in the local hash tool. Explain why hashing the literal text of its hex display would be a different experiment.
Challenge two: reconstruct the path
Use B and parent CD as A’s proof siblings in the four-leaf model. State the sorted-pair rule and compare the computed root with the expected fixture.
Challenge three: change the convention
Replace odd-node promotion with duplication in a three-leaf example. Predict that the construction and potentially the root differ even when the original text values are unchanged.
Finish with the trust question
Explain who chose the accepted root and which claim the proof establishes. Do not extend membership into claims about economic value, current balances or finalized inclusion without separate evidence.
Follow the proof model
Convention: UTF-8 leaves, Keccak-256, lexicographically sorted hash pairs
leaf A: 0x03783fac2efed8fbc9ad443e592ee30e61d65f471140c10ca155e937b435b760
sibling B: 0x1f675bff07515f5df96737194ea945c36c41e7b4fcef307b7cd4d0e602a69111
parent AB: 0x69de756fea16daddbbdccf85c849315f51c0b50d111e3d2063cab451803324a0
sibling parent CD: 0xe62e1dfc08d58fd144947903447473a090c958fe34e2425d578237fcdf1ab5a4
root: 0x4e2b32e9c7b10ee15f38192ed65b95656a84e32531157b9384ef0d3cabe95956Binary examples use the stated local playground convention. They are not Ethereum account or storage trie proofs.
What must match between a tree builder and verifier?
A root is meaningful under the entire agreed construction.
Original explanations by EtherTools. Examples are educational and source-linked; this site is independent of the Ethereum Foundation. Our approach.