Sustained Participation as a Security Resource: The Bounded Participation Channel
Bounded Participation Channel makes sustaining many identities pay a recurring per-window participation cost.
The Bounded Participation Channel is a primitive that repeatedly verifies identity-bound participation under a deadline, rather than only pricing identity creation. Its properties—binding, freshness, real-time response, and bounded per-channel throughput—yield a cost floor of at least sT/τ_h channel-windows to sustain s identities over T windows, for human, AI, or hybrid solvers. A hash-based construction was evaluated against GPT-4o, Gemini 2.5 Flash, and Claude Sonnet 4.5 across 600 trials; perceptual-task accuracy was 97–100%, but automated throughput remained bounded.
- BPC re-verifies each identity with a fresh deadline-bound challenge every window.
- Required properties are binding, freshness, real-time response, and bounded throughput.
- Sustaining s identities for T windows costs at least sT over tau_h channel-windows.
- Hash-based proofs were tested in 600 trials on three frontier models.
- Accuracy of 97-100% still left automated channels throughput-bounded.
Full article212 words · extracted from arxiv.org · click to collapse
Can sustained, per-identity participation be engineered into a security resource? Most anti-Sybil defenses price identity creation rather than identity survival. Once admitted, an adversary may sustain many identities without paying a recurring cost. We introduce the Bounded Participation Channel (BPC), a formal primitive for repeatedly verifying participation window by window. BPC issues fresh, identity-bound challenges under a strict deadline and enforces four structural properties: identity binding, freshness, real-time response, and bounded per-channel throughput. Together, these yield a provable cost theorem: sustaining $s$ identities over $T$ windows requires $C(s,T) \geq sT/τ_h$ participation channel-windows. The guarantee is solver-agnostic: a channel may be operated by a human, an AI system, or a hybrid. We give a hash-based construction with publicly verifiable participation proofs, characterize four admissible challenge families, and evaluate two against GPT-4o, Gemini 2.5 Flash, and Claude Sonnet 4.5 across 600 trials. Despite near-perfect accuracy (97--100%) on the perceptual tasks, the evaluated automated channels remain throughput-bounded under the tested deployment conditions. The results illustrate a key distinction: solvability does not imply unlimited throughput. By requiring participation to be re-earned by every identity in every time window, BPC turns sustained participation into a measurable security resource with a linear structural cost floor, independent of whether the participation is supplied by humans, AI systems, or hybrids.
Text extracted automatically; images, tables and formatting may be missing. Original: https://arxiv.org/abs/2609.35300