TYPE 0x0904 · LEGACY FAMILY

P2WPKH_LEGACY

Legacy P2WPKH (pay-to-witness-pubkey-hash) wrapped as a typed Ladder Script block. Identical evaluation to P2PKH_LEGACY — HASH160 check + signature verify. Represents the segwit migration path.

Legacy Non-Invertible

Ladder Diagram

Fields

Field	Data Type	Size	Side	Description
hash160	HASH160	20 B	Conditions	RIPEMD160(SHA256(pubkey)) commitment. Node-computed — the user provides PUBKEY and the node computes this field automatically. Raw hash input is rejected.
pubkey	PUBKEY	32-33 B	Witness	Public key — provided by the user. The node derives HASH160 from this key at creation time. Revealed at spend time.
signature	SIGNATURE	64-65 B	Witness	Signature over the transaction sighash

Wire Format Breakdown

Conditions side (in scriptPubKey):

0x0904 0 1 HASH160 · 20B = 26 bytes

Witness side (in input witness):

0x0904 0 2 PUBKEY · 33B SIGNATURE · 64B = 105 bytes

Total (conditions + witness) 131 bytes

With rung overhead included. Compressed pubkey (33B) case.

Evaluation Logic

1. Delegates to EvalP2PKHLegacyBlock directly — the wrapper exists only to give P2WPKH a distinct block-type ID. Field, hash, and sig semantics are byte-identical to P2PKH_LEGACY.

2. Locate HASH160, PUBKEY, SIGNATURE; any missing → ERROR. HASH160 not exactly 20 B → ERROR

3. Compute CHash160(PUBKEY); memcmp mismatch → UNSATISFIED

4. Dispatch VerifySigWithScheme via the Ladder LadderSigChecker; result is the block result.

Return Values

Condition	Result
Missing HASH160, PUBKEY, or SIGNATURE	ERROR
HASH160 wrong size (not 20B)	ERROR
HASH160(PUBKEY) != committed hash	UNSATISFIED
Signature fails	UNSATISFIED
Signature valid	SATISFIED

JSON Wire Format

Conditions (committed in the rung leaf)

{
  "type": "P2WPKH_LEGACY",
  "inverted": false,
  "fields": [
    { "type": "HASH160", "hex": "89abcd...20 bytes" }
  ]
}

Witness (input)

{
  "type": "P2WPKH_LEGACY",
  "inverted": false,
  "fields": [
    { "type": "PUBKEY", "hex": "02abc1...33 bytes" },
    { "type": "SIGNATURE", "hex": "e5f6a7...64 bytes" }
  ]
}

Notes

Functionally identical to P2PKH_LEGACY.
The HASH160 field is node-computed: the user supplies PUBKEY and the node derives the hash commitment automatically. Submitting a raw HASH160 value directly is rejected.
Kept as a separate type code to represent the distinct segwit migration path.
In Bitcoin, P2WPKH moved witness data outside the transaction body for fee savings. In Ladder Script, the distinction is semantic only.

Use Cases

Segwit Migration Path

Represents the SegWit P2WPKH migration. Identical evaluation to P2PKH_LEGACY.

Witness Discount Compatibility

Maintains the conceptual distinction from P2PKH for users migrating from segwit outputs.

← P2SH_LEGACY P2WSH_LEGACY →