Merkle proofs

Merkle proof cells verify that some cell tree data belongs to the full tree. This design allows the verifier to avoid storing the entire tree’s content while still being able to verify the content using the root hash.

A Merkle proof cell contains exactly one reference c. Its level 0 <= l < 3 is max{Lvl(c) - 1, 0}.

Each Merkle proof cell serializes as follows:

• one tag byte with value 0x03;
• the 256-bit first higher hash of the referenced cell c or the representation hash of c if its level equals zero;
• 2 bytes that store the depth of the deleted subtree that was replaced by the reference.