Economic Attack Surface and Boundary Enforcement

WAproxy must enforce strict economic boundaries to prevent abuse.

Execution endpoints represent financial operations.
They are potential attack surfaces.

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ATTACK CATEGORY 1 — DUST FLOODING
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Attempt:
Send extremely small amounts repeatedly.

Defense:
Enforce per-coin min_send thresholds.

Rule:
amount_sat >= coin_min_send_sat

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ATTACK CATEGORY 2 — FEE GAMING
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Attempt:
Exploit rounding behavior in protocol fee calculation.

Defense:
- Integer-only arithmetic
- Basis-point calculation
- Deterministic rounding discipline

protocol_fee = amount_sat × FEE_BPS / 10000

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ATTACK CATEGORY 3 — IDEMPOTENCY ABUSE
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Attempt:
Reuse idempotency keys to manipulate execution.

Defense:
- Persist (wallet_id, idempotency_key)
- Reject parameter mismatch
- Return deterministic conflict error

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ATTACK CATEGORY 4 — BALANCE DRAIN EDGE CASE
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Attempt:
Send full balance without safety margin.

Defense:
Require:

wallet_balance >= amount_sat + safety_margin

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ATTACK CATEGORY 5 — CONCURRENCY RACE
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Attempt:
Submit parallel sends from same WID.

Defense:
- Wallet-level locking
- Atomic state transitions
- Serialized execution

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BOUNDARY PRINCIPLE
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WAproxy does not attempt to:

- optimize user strategy
- dynamically alter economic rules
- speculate on network behavior

It enforces deterministic boundaries.

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DESIGN INVARIANTS
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- All arithmetic is integer.
- All economic limits are explicit.
- All retries are deterministic.
- All state transitions are atomic.
- All validation occurs before broadcast.

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ARCHITECTURAL STATEMENT
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Economic discipline is mandatory
for deterministic execution safety.

WAproxy protects execution boundaries,
not market outcomes.