Lamport & Merkle Visualizer

1. Lamport one-time signature

For demo legibility we use a truncated $n$-bit hash. Each row of the secret-key grid is a pair $(s_{i,0}, s_{i,1})$; one of the two is revealed per signature, with the choice determined by the bit $h_i$ of the message hash.

Hash size $n$ (bits)

Message

Press "Keygen" to start.

2. Merkle tree over Lamport leaves

Build a binary Merkle tree of height $h$ with $2^h$ Lamport key pairs at the leaves. Public key = the root, $n$ bytes. Signature on the $j$-th leaf = (Lamport sig + Lamport pk + $h$ auth-path nodes).

Tree height $h$

Leaf index $j$ to sign

Message

signed leaf auth-path sibling recompute path to root root (public key)

100% Scroll horizontally / vertically inside the box.

Press "Build tree" to start.