Proof-of-Presence (PoP) Protocol
Overview
Proof-of-Presence (PoP) is a decentralized protocol for producing cryptographically verifiable attestations of physical presence.
It allows applications, businesses, and smart contracts to confirm that a user, device, or participant was physically present at a specific place and time, under a predefined level of assurance, without relying on centralized location providers or exposing raw location data.
PoP introduces a neutral, trust-minimized presence layer that transforms real-world actions into verifiable, auditable, and programmable events suitable for Web3, DePIN, and hybrid Web2/Web3 systems.
Motivation and Problem Statement
An increasing number of digital products depend on events in the physical world, including:
visiting a location or venue
attending an event
interacting with a physical object or terminal
completing a route or task in real space
Despite this demand, existing location and check-in systems exhibit structural weaknesses:
Centralization: physical presence data is controlled by OS vendors, API platforms, and large technology providers
Lack of verifiability: GPS, QR check-ins, and self-reported signals are easy to spoof or replay
Privacy leakage: raw coordinates and trajectories are over-collected and reused without user control
Economic fragility: when rewards or access depend on presence, fraud becomes economically rational
As a result, there is no open infrastructure that allows independent, privacy-preserving, and economically robust confirmation of physical presence.
PoP is designed to fill this gap.
Design Principles
PoP is built around the following core principles:
Trust Minimization
No single device, sensor, or infrastructure operator is treated as a source of truth.
Presence is confirmed through independent cross-validation and cryptographic verification.
Event-Based Verification
PoP verifies facts, not raw coordinates.
The protocol answers statements such as:
“This participant was present in zone X during time window T under policy P.”
rather than exposing exact location traces.
Privacy-by-Design
PoP minimizes data disclosure by default:
raw coordinates are not published on-chain
attestations rely on cryptographic commitments
optional zero-knowledge proofs allow confirmation without revealing location data </aside>
Resistance to Incentivized Attacks
PoP is designed for environments where presence has economic value.
The protocol explicitly addresses spoofing, replay attacks, Sybil behavior, validator collusion, and infrastructure manipulation.
Policy-Driven Assurance
Different use cases require different levels of certainty.
PoP supports configurable verification policies, allowing applications to trade off cost, latency, and assurance.
PoP Attestation Model
The primary output of the protocol is a PoP Attestation — a standardized, verifiable object that represents a confirmed physical event.
A PoP Attestation includes:
event type (visit, route, interaction, participation)
identifier of the target zone, point, object, or route
time window of the event
cryptographic commitment to evidence
verification policy used
validator confirmations or aggregated proof
confidence and assurance metadata
The attestation is:
independently verifiable
suitable for smart-contract consumption
auditable by third parties
compatible with cross-chain environments
Architecture Overview
PoP is implemented as a multi-layer verification system, separating event generation, validation, and publication.
Event Generation Layer (Edge)
This layer interfaces with the physical world and produces PoP Events using:
mobile SDKs (GNSS, Wi-Fi, BLE, inertial context, optional sensors)
infrastructure devices (beacons, terminals, IoT nodes)
hybrid interaction points (QR, NFC, proximity triggers)
Each PoP Event is a pseudonymized, cryptographically bound artifact that represents a claim of presence but is not yet considered verified.
Validation Layer (Oracle and Validator Network)
PoP Events are processed by a decentralized network of validators with specialized roles:
Witness nodes — structural and temporal validation
Geo-verifiers — spatial and contextual consistency checks
Consistency validators — behavioral analysis and anti-fraud detection
Zero-knowledge processors (optional) — validation of privacy-preserving claims
Events are confirmed through local consensus per event, producing a finalized PoP Attestation once quorum requirements are met.
Publication Layer (On-Chain and Off-Chain)
PoP separates verifiability from data exposure:
on-chain: commitments, hashes, policy identifiers, validator proofs
off-chain (optional): encrypted evidence under controlled access
This design enables smart contracts to verify presence without requiring access to sensitive data.
Verification Policies
PoP supports multiple assurance levels, selectable per use case:
Light Policy — low-cost, high-volume scenarios (marketing, gamification)
Standard Policy — commercial-grade confirmation (business access, medium-risk DePIN)
High Assurance Policy — critical events (financial triggers, logistics, high-value rewards)
Each policy defines:
required signal classes
validator quorum and roles
mandatory anti-fraud checks
publication format
resulting confidence score
Economic Model
PoP introduces an explicit economic layer around presence verification as a service.
Key characteristics:
verification cost scales with assurance level, not data volume
validators and infrastructure operators are economically incentivized to act honestly
reputation and staking mechanisms discourage low-quality or malicious behavior
protocol fees support sustainability, security, and ecosystem growth
This model allows PoP to support both mass adoption scenarios and high-value confirmations without compromising security.
Scope and Applicability
PoP is designed as a general-purpose presence verification protocol applicable to:
DePIN networks
loyalty and reward systems
access control and entitlement gating
on-chain triggers based on real-world actions
logistics, events, and physical-digital integrations
By abstracting physical presence into verifiable attestations, PoP enables new classes of applications that require trust in real-world actions without centralized intermediaries.
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