Merkle Tree Batch Verification

Batch Ledger

Batches in ledger 8

Select batch #0

Show Merkle proof path (vs. full re-scan)

Cascade animation speed 1.0×

Live State

Root: —

Hashes recomputed (tamper)

Records in ledger

Proof path length

Full re-scan length

Verification speed-up

2.7×

How it works

Every batch record is hashed into a leaf. Each internal node's hash is the hash of its two children concatenated, all the way up to a single root hash:

leaf[i]     = H(record[i])
node[p]     = H( node[2p+1] || node[2p+2] )
root        = node[0]

This is exactly how a pharmaceutical batch ledger (or a Bitcoin block, or Git's object store) proves data integrity: the root hash is a single 32-bit fingerprint of every record beneath it.

Tamper — mutates one batch's data. Its leaf hash changes completely (the avalanche effect: one flipped character flips roughly half the output bits), and that change cascades up every ancestor to the root — only log₂(n) hashes are recomputed, shown in orange.
Merkle proof — to prove batch #k is untampered, a verifier only needs the log₂(n) sibling hashes on the path to the root, not the other n−1 records. Toggle the checkbox to compare that proof path against a naive full re-scan of every leaf.
Hash function — a real, deterministic FNV-1a mix (32-bit), matching the "hash → fixed-size digest, tiny input change → unrelated output" property that SHA-256 provides in production blockchains.

Real-world relevance: this Merkle-proof mechanism is what lets a pharmacist verify a single drug batch's authenticity against a blockchain root hash published by the manufacturer, without downloading the entire supply-chain ledger.

Unchanged node Recomputed (cascade) Merkle proof node

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.