The study, authored by Lacour M. Ayompe of the University of California, Irvine, and Franklin M. Lartey of Lartey Research & Management, synthesizes 116 core studies drawn from an initial pool of roughly 1,420 records spanning civil engineering, cybersecurity, urban planning, and public administration. Using Torraco’s integrative conceptual review methodology, the authors screened 889 unique titles and abstracts down to 232 full-text studies before arriving at their final sample, covering publications from 2010 to 2025. The result is not an empirical case study but a category-defining architecture, complete with testable hypotheses, intended to guide future field research.

At the heart of the paper is a diagnosis the authors call the trust deficit. Drawing on Principal-Agent Theory and Information Asymmetry Theory, they describe how municipal project owners, the principals, delegate physical execution to specialized contractors, the agents, who inevitably hold superior real-time knowledge of actual site conditions, work quality, and material usage. Because field work happens far from central offices, managers often cannot objectively confirm that contracted tasks were completed at the right location, at the intended time, and to specification. The authors define the trust deficit as the systematic inability of a principal to convert an agent’s claims into decision-grade, audit-proof physical evidence without incurring prohibitive transaction costs.

The consequences, according to the synthesis, ripple far beyond administrative annoyance. Without robust verification, errors and substandard workmanship go undetected until late in the project lifecycle, driving avoidable rework, material waste, and schedule slippage. Payment cycles stall while invoices await manual reconciliation, straining contractor cash flows. Perhaps most strikingly for climate-conscious cities, the traditional model depends on physical inspection trips, so-called truck rolls, that consume fossil fuel and directly inflate municipal Scope 3 greenhouse gas emissions. Fragmented paperwork also undermines chain-of-custody assurances and ESG reporting accuracy, leaving public agencies vulnerable to failed audits and financial penalties.

The proposed remedy is a five-phase lifecycle that transforms work orders into structured, machine-readable data schemas. Phase one, Task Assignment and Standardization, specifies precise requirements, compliance checklists, and the exact visual evidence needed before crews ever arrive on site. Phase two, Remote Work Documentation, captures geotagged photos, high-resolution video, and secure timestamps of before, during, and after states, anchoring evidence to the exact project location. Phase three, Quality Validation, moves review onto centralized digital dashboards where engineers check location accuracy and technical compliance remotely. Phase four, Payment Readiness, automatically queues invoices or triggers audit-verified payments once submissions are approved, and phase five, Performance Tracking, aggregates the resulting data into contractor scorecards, carbon metrics, and portfolio-level analytics.

The authors illustrate the lifecycle with a hypothetical municipal water main replacement: a public works authority issues a digital task package specifying trenching depth and compaction density; the contractor captures encrypted, geotagged, time-stamped images of the laid pipe before backfilling; quality assurance engineers cross-reference spatial coordinates against underground utility maps on a digital twin dashboard without dispatching a vehicle; an automated gateway generates an audit-certified invoice trigger; and the completed job updates reliability scorecards while logging the emissions saved from the eliminated site visit.

One of the paper’s most technically significant contributions is its confrontation with what blockchain researchers call the Oracle Problem. Distributed ledger technology guarantees only that a record, once written, cannot be altered; it says nothing about whether the record reflects reality. If a field worker uploads spoofed GPS coordinates or recycled photographs, a blockchain will simply record that fraudulent data immutably. To close this vulnerability, VaaS incorporates multi-factor physical-to-digital validation at the point of capture, including hardware-level cryptographic attestation through Trusted Execution Environments, anti-spoofing geofencing that combines GPS, cell tower triangulation, and Wi-Fi mapping, cryptographic time-stamping, and automated metadata integrity checks. Crucially, the authors position VaaS not as a replacement for Building Information Modeling, digital twins, or blockchain, but as an overarching governance layer that orchestrates these tools and enforces verification protocols before data ever reaches a ledger.

The framework also grapples candidly with privacy and labor concerns that could otherwise derail adoption. Continuous GPS tracking of field workers raises psychological stress, workforce resistance, and legal exposure under GDPR and CCPA. The authors therefore reject continuous surveillance in favor of event-triggered data capture aligned with GDPR Article 5(1)(c) data minimization principles: spatial and personal metadata are recorded only at the instant a worker manually submits a verification photo or measurement. Automated masking and blur filters redact facial features and non-essential background details in public spaces, and W3C Verifiable Credentials and Decentralized Identifiers authenticate workers and devices without exposing personal identification data. Offline-capable capture modes and physical fallback pathways accommodate poor connectivity and contexts where remote review alone is insufficient.

To model the framework’s cumulative impact, the authors propose a Value Proposition Pyramid with four ascending layers. The Functional Layer establishes the technical machinery of geotagged, time-stamped, privacy-preserving evidence capture. The Operational Layer translates that foundation into day-to-day efficiencies, with external benchmark studies in related digitized workflow domains reporting quality control cost reductions of 50 to 70 percent, figures the authors explicitly frame as contextual reference points rather than outputs of their model. The Strategic Layer links verified work to financial flow, with external studies observing payment timeline improvements benchmarked between 30 and 60 percent, alongside audit-ready compliance records. At the pinnacle, the Ecosystem Layer envisions trust established through verifiable provenance rather than historical reputation, reshaping norms of accountability across entire project networks.

The paper formalizes its claims in a Theory of Change with testable hypotheses: that a shared, authenticated verification ledger will decrease multi-stakeholder dispute rates; that event-triggered, privacy-preserving capture will achieve higher worker acceptance than continuous tracking; that auditable digital evidence integrated into payment workflows will reduce invoice disputes and accelerate disbursement; and that standardized remote verification will cut field-to-office cycle times and Scope 3 inspector-transit emissions. The authors also speculate that digital provenance trails may eventually become a regulatory baseline for public procurement, much as safety protocols evolved from optional best practices into statutory requirements, potentially shifting market advantage from relational capital to empirically demonstrated performance.

The authors are careful to acknowledge the framework’s limits. As an unvalidated conceptual review, VaaS remains a theoretical architecture whose gains depend on disciplined data capture, sustained organizational commitment, and careful management of software infrastructure costs against net return on investment. Boundary conditions are explicit: the framework suits objective, quantifiable, location-bound tasks such as verifying trenching depth, pipe installation, or rebar placement, but is unsuitable for subjective aesthetic evaluations or design decisions requiring nuanced human judgment. Future validation, the authors suggest, should proceed in phases, from quasi-experimental field trials measuring cycle times and emissions, to financial analyses of invoice-to-cash acceleration, to longitudinal studies of multi-stakeholder trust across smart city networks. If those tests bear out the theory, the humble inspection visit, with its clipboard, fuel bill, and carbon footprint, may give way to a future in which every shovel of dirt, every laid pipe, and every payment is verified by data rather than assumed in trust.

Subject of Research: A conceptual framework for digital, remote verification of decentralized infrastructure and smart city field operations

Article Title: Trust but verify: a Verification-as-a-Service framework for sustainable infrastructure governance—An integrative conceptual review

Article References: Ayompe, L. M., & Lartey, F. M. (2026). Trust but verify: a Verification-as-a-Service framework for sustainable infrastructure governance—An integrative conceptual review. Frontiers in Sustainable Cities, 8, Article 1975063. https://doi.org/10.3389/frsc.2026.1975063

Image Credits: AI Generated

DOI: 10.3389/frsc.2026.1975063

Keywords: Verification-as-a-Service, smart cities, infrastructure governance, trust deficit, principal-agent theory, blockchain, digital twins, BIM, remote inspection, Scope 3 emissions, GDPR, ESG compliance