Module trace 

Header chain trace encoding for ligerito polynomial commitment proofs.

Encodes block headers into a trace polynomial that ligerito can prove over. The trace layout binds block hashes, prev_hash linkage, difficulty progression, state roots at epoch boundaries, and a sentinel row with tip NOMT roots.

Trace layout (32 fields per header)

Field  0:      height
Fields 1-8:    block_hash (32 bytes = 8 × 4-byte LE fields)
Fields 9-16:   prev_hash  (32 bytes = 8 × 4-byte LE fields)
Field  17:     nBits (compact difficulty target)
Field  18:     cumulative_difficulty (lower 32 bits)
Field  19:     running header commitment (Blake2b-512 chain, lower 4 bytes)
Fields 20-23:  sapling_root (16 bytes, epoch boundaries only)
Fields 24-27:  orchard_root (16 bytes, epoch boundaries only)
Fields 28-29:  nullifier_root (8 bytes, epoch boundaries only)
Field  30:     state_commitment (Blake2b-512 chain, lower 4 bytes)
Field  31:     reserved

After all headers, a sentinel row of 24 fields:

Fields 0-7:   tip_tree_root (32 bytes)
Fields 8-15:  tip_nullifier_root (32 bytes)
Fields 16-23: final_actions_commitment (32 bytes)

Public outputs are extracted from fixed trace positions by the prover and bound to the Fiat-Shamir transcript. The Ligerito proximity test does NOT constrain these values — soundness relies on the honest-prover assumption plus cross-verification against independent nodes.

Structs

EpochStateRoots

State roots at an epoch boundary.

HeaderChainTrace

Header chain trace for ligerito proving.

TraceHeader

Header data for trace encoding. Minimal fields needed. No full block data, just what goes into the trace.

Constants

FIELDS_PER_HEADER

Fields encoded per block header in the trace polynomial.

TIP_SENTINEL_SIZE

Sentinel row appended after all headers. Contains tip_tree_root, tip_nullifier_root, final_actions_commitment.

Functions

bytes_to_field

Convert 4 bytes (LE) to a BinaryElem32 trace field.

encode_trace

Encode headers into a trace polynomial for ligerito proving.

hex_to_bytes

Hex string to bytes.

nbits_to_difficulty

Convert nBits (compact difficulty target) to difficulty value.

parse_tree_root_bytes

Derive tree root hash from zebrad’s hex-encoded final state string.

update_running_commitment

Running header commitment chain (Blake2b-512, truncated to 32 bytes).

update_state_commitment

Running state commitment chain (Blake2b-512, truncated to 32 bytes).