XRPL Proposal Would Price Out Front-Running by Turning Attack Spend Into Holder Fees
Schwartz-authored fee-curve design caps reserved slots at 32/ledger, pushes attacker costs to ~3x base fee, with proceeds flowing to XRP fee-earners.
XRP changed hands at $1.08, up 2.46% over 24 hours, as a technical proposal from Ripple CTO Emeritus David Schwartz circulated on X targeting front-running and sandwich attacks on the XRP Ledger. The mechanism’s relevant number for market structure isn’t price — it’s the fee multiple attackers would be forced to pay to sustain a denial-of-service attempt: up to roughly 3x the base transaction fee.
The Mechanics: Slot Reservations and a Rising Fee Curve
The design introduces a new ledger object, ReservedTxns, alongside a new transaction type, TxnReserve. Users would pay at least 2x the standard fee to reserve an execution slot in a future ledger, with reservations limited to 16 ledger intervals ahead and an initial cap of 32 reserved slots per ledger.
Pricing isn’t static. Once a given window fills past 50% capacity, reservation costs begin climbing, approaching roughly 3x base fee as slots run out. An attacker trying to lock out legitimate users across consecutive future ledgers would need to keep paying that escalating rate every few seconds, indefinitely, to hold the blockade.
Separately, reserved transactions are only broadcast after the prior ledger’s consensus round is effectively finalized — shrinking the observation window that currently lets an actor see a pending transaction and insert a competing one ahead of it, the mechanical root of front-running and sandwich extraction on XRPL.
Attack Economics: Cost Escalation as the Deterrent
Schwartz’s framing treats the fee curve as an economic filter rather than a technical block. In his words: “If that happens, we can just raise the cost of the attack, and it would either stop or be, in effect, a huge financial gift from state actors to XRP holders.”
Pushback in the same thread centered on whether a well-capitalized state or state-sponsored actor could simply absorb the elevated fees and sustain an attack regardless of cost. Schwartz’s response reframed the incentive math: “It seems very weird to me to worry that any state actors or state-sponsored actors would want to give thousands of dollars an hour to XRP holders just to make the XRPL no more vulnerable to front running and sandwich attacks than it is now.”
Under the model, any fee spend from a sustained attack doesn’t burn or vanish — it accrues to network participants earning transaction fees, converting hostile activity into a direct transfer to XRP holders rather than a pure network cost.
Parameters Remain Governance-Adjustable
None of the figures are proposed as fixed constants. Schwartz indicated the 32-slot ceiling and the 2x-to-3x fee range would run through XRPL’s existing validator governance process, with room to expand capacity if legitimate reservation demand rises with usage data over time.
The proposal has not been implemented on mainnet and remains at the community-discussion stage. For traders tracking XRPL fundamentals, the relevant signal isn’t price impact but design philosophy: the network is opting to price out MEV-style extraction economically rather than filter it algorithmically, with attacker cost becoming holder yield rather than lost value.
Read more: XRP’s Q3 Seasonality: A 3-for-3 Rebound Record After Consecutive H1 Losses
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