High-Risk AI Systems and the Problem of Identity in the European AI Act

2026-04-17

AI Summary

This study addresses a critical operational gap in the EU AI Act, which imposes lifecycle regulation on high-risk AI systems yet lacks clear criteria for determining their synchronic identity. To resolve this, the paper introduces—for the first time in AI governance—the function+ framework from artifact identity theory, individualizing AI systems through their intended functions and trustworthiness characteristics to establish an auditable mechanism for synchronic identity assessment. Integrating conceptual analysis from philosophy and law, trustworthiness modeling, and compliance audit design, the work proposes two concrete measures: first, mandating more precise and testable statements of intended purpose; and second, instituting a standardized, auditable trustworthiness reporting mechanism. Together, these enable reliable identity comparisons across time and deployments, thereby filling a key implementational void in current regulatory practice.

Abstract

The EU Artificial Intelligence Act (AIA) establishes a lifecycle governance regime for high-risk AI systems built around ex-ante conformity assessment, post-market monitoring, and re-assessment upon"substantial modification."These obligations presuppose AI identity judgments: regulators and providers must decide when an updated system remains the same system over time. In this work, we show how this logic is clarified by the function+ framework of artifact identity, which individuates AI systems by their intended function together with context-sensitive criteria of appropriate functioning, captured as"AI trustworthiness."We further argue that the AIA does not provide an internal, auditable criterion for synchronic identity--when two AI systems at a given time should count as the same for regulatory purposes--and instead largely defers such sameness determinations to sectoral or harmonization instruments. function+ supplies a synchronic identity test anchored in intended function and trustworthiness profiles and levels, making synchronic identity decisions inspectable in governance settings such as procurement, liability, and market surveillance. Our contribution is a conceptual and auditing lens: we provide a correspondence map between AIA lifecycle obligations and function+ identity components, and we make the synchronic case operationally legible via a minimal decision flow for audit and dispute contexts. We conclude with two implementation-facing recommendations: (1) more precise, testable reporting of intended purpose, and (2) standardized, auditable trustworthiness reporting that supports comparability over time and across deployments.

Problem

• AI identity
• European AI Act
• high-risk AI systems
• synchronic identity
• regulatory compliance

Innovation

• AI identity
• function+ framework
• European AI Act
• trustworthiness
• conformity assessment