
Briefing
The core problem of permissionless blockchains is their vulnerability to denial-of-service attacks, where low-value transactions clog the network and inflate fees, often requiring costly, centralized, or fee-market-dependent solutions. This research proposes STARVESPAM, a foundational breakthrough that implements a local reputation system at the peer-to-peer transaction relay layer. This mechanism allows individual nodes to dynamically monitor and throttle misbehaving peers based on behavioral signals, such as transaction rate and duplication, without requiring global consensus. The single most important implication is the creation of a robust, adaptive defense layer that maintains network liveness and fairness, fundamentally stabilizing the decentralized transaction processing architecture.

Context
Prevailing theoretical limitations in blockchain security center on the reliance on global, protocol-level mechanisms ∞ primarily transaction fees ∞ to regulate resource consumption and deter spam. This established model, however, creates an exploitable attack vector where a well-funded adversary can overwhelm the network by simply paying the required fee, leading to periods of congestion, high costs for honest users, and potential chain halts, illustrating a core vulnerability in economic-only security models.

Analysis
The paper introduces the local reputation primitive, a decentralized filtering algorithm that operates independently at each node in the mempool and relay layer. The mechanism fundamentally differs from previous approaches by shifting the security burden from the consensus layer to the peer-to-peer communication layer. Each node maintains a local score for its direct peers, calculated from observed behavioral signals like excessive transaction rate, high failure rates, and transaction duplication.
When a peer’s score drops below a dynamic threshold, the node throttles that peer’s resource access, effectively isolating the source of the spam without needing network-wide agreement or a change to the block production rules. This localized, adaptive defense provides immediate, autonomous mitigation.

Parameters
- Defense Layer Location ∞ Transaction Relay Layer. This is the peer-to-peer communication channel before block inclusion, where the filtering mechanism is implemented.
- Reputation Scope ∞ Local Peer-to-Peer. Each node makes filtering decisions autonomously based only on the behavior of its direct neighbors.
- Simulation Node Count ∞ 100 Nodes. The system’s effectiveness was validated in a simulation environment of this size.
- Spam Propagation Reduction ∞ Stopped after a few hops. The local filtering prevented most spam from reaching the majority of the network.

Outlook
Future research will focus on formalizing the game-theoretic stability of local reputation systems and integrating this mechanism into existing mempool architectures to achieve provable fairness guarantees. This new avenue of research unlocks the potential for truly robust, high-throughput decentralized networks within 3-5 years, where network liveness is protected by an adaptive, localized defense, allowing the core consensus mechanism to focus purely on state finality.

Verdict
The introduction of local reputation as a decentralized spam primitive fundamentally strengthens the resilience of the peer-to-peer communication layer against adversarial resource exhaustion.
