Module domain 

Registered domain selectors for protocol-visible hash commitments.

This module follows the Miden domain-separation RFC (https://github.com/0xMiden/crypto/pull/1026): consensus-critical domains use registered numeric identifiers rather than hashed strings, packed as

selector = (domain_id << 8) | version

with domain_id a registered 24-bit integer (>= 1) and version an 8-bit per-domain version (>= 1). The selector rides in the second capacity element of the Poseidon2 sponge (hash_elements_in_domain); the first capacity element carries the padding rule, and the third marks empty input. The fourth capacity element is zero in the initial framing state.

Provisional registry entries

The RFC’s draft registry allocates 0x010000..0x01ffff to miden-vm, with concrete entries delegated to this repository. These are the range’s first entries, to be migrated into the machine-readable registry when it lands:

domain_id	version	domain
0x010000	1	kernel commitment (KERNEL_DOMAIN_TAG)
0x010001	1	execution claim (CLAIM_DOMAIN_TAG)
0x010002	1	proof request key (PROOF_REQUEST_DOMAIN_TAG)

Selectors share one capacity namespace with the merge_in_domain values used for MAST control-block hashing. Those are opcode-sized (< 256) while every registered selector is >= 257 (domain_id >= 1), so those two ranges cannot collide. Distinctness among registered selectors is the registry’s responsibility: each domain_id is allocated once within its maintainer’s range, and the three defined here are pinned distinct by registry_entries_are_valid_and_distinct_selectors.

Constants

EXECUTION_CLAIM_DOMAIN_ID

Registered domain id for the execution-claim commitment.

KERNEL_COMMITMENT_DOMAIN_ID

Registered domain id for the kernel commitment.

PROOF_REQUEST_DOMAIN_ID

Registered domain id for the proof-request key.

Functions

domain_selector

Packs a registered domain id and per-domain version into a domain selector.