TYPE 0x0705 · COMPOUND FAMILY

CLTV_SIG

Signature verification combined with an absolute timelock (CLTV) in a single block. Collapses the common SIG + CLTV two-block pattern, saving 8 bytes on wire.

Compound Non-Invertible

Ladder Diagram

Fields

Field	Data Type	Size	Side	Description
scheme	SCHEME	1 B	Conditions	Signature scheme selector (Schnorr, ECDSA, or PQ)
locktime	NUMERIC	1-4 B	Conditions	Absolute locktime (block height)
pubkey	PUBKEY	32-33 B	Witness	Public key (verified via Merkle leaf)
signature	SIGNATURE	64-65 B	Witness	Schnorr signature (64B) or with sighash byte (65B)

Public key folded into Merkle leaf via merkle_pub_key (PubkeyCountForBlock = 1). No key field in conditions.

Evaluation Logic

1. Verify witness PUBKEY against Merkle leaf (merkle_pub_key). If mismatch → UNSATISFIED

2. Check for SCHEME field. If PQ scheme, route to post-quantum verifier.

3. Verify SIGNATURE against PUBKEY. If invalid → UNSATISFIED

4. Verify CheckLockTime(locktime). If nLockTime < committed value → UNSATISFIED

5. Both checks passed → SATISFIED

Return Values

Condition	Result
Missing required fields	ERROR
Merkle leaf verification fails	UNSATISFIED
Signature verification fails	UNSATISFIED
CLTV locktime check fails	UNSATISFIED
Signature valid AND locktime reached	SATISFIED

JSON Wire Format

Conditions (scriptPubKey)

{
  "type": "CLTV_SIG",
  "inverted": false,
  "fields": [
    { "type": "PUBKEY", "hex": "02abc1...33 bytes" },
    { "type": "SCHEME", "value": 1 },
    { "type": "NUMERIC", "value": 850000 }
  ]
}

Witness (input)

{
  "type": "CLTV_SIG",
  "inverted": false,
  "fields": [
    { "type": "PUBKEY", "hex": "02abc1...33 bytes" },
    { "type": "SIGNATURE", "hex": "30440...64 bytes" }
  ]
}

Use Cases

Time-Locked Rewards

Mining pool payouts locked until a specific block height. The recipient has the key but cannot spend until the chain reaches the committed height, enforcing vesting schedules on-chain.

Scheduled Payments

Pre-signed transactions that become valid at a future date. Combined with a signature in one block, the payment is authorized but time-gated.

Refund Paths in HTLCs

The refund branch of an atomic swap uses CLTV_SIG: if the counterparty doesn't claim within the absolute deadline, the original sender can reclaim funds with their signature.

← PTLC TIMELOCKED_MULTISIG →