Future-Proofing AI Audits Against Quantum Threats

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Author: Denis Avetisyan

As artificial intelligence systems become increasingly regulated, ensuring the long-term security and integrity of their audit trails is paramount.

This review details quantum-adversary-resilient evidence structures and migration strategies for regulated AI audit trails, focusing on secure logging and formal security definitions.

The increasing reliance on cryptographic audit trails for regulated AI systems creates a vulnerability to future quantum computing threats. This paper, ‘Quantum-Adversary-Resilient Evidence Structures and Migration Strategies for Regulated AI Audit Trails’, addresses this challenge by formalizing security definitions for quantum-resistant evidence structures and exploring viable migration strategies for existing audit logs. We demonstrate that, under standard assumptions, hash-and-sign instantiations leveraging post-quantum signatures can provide robust integrity, non-equivocation, and binding properties, even against quantum adversaries. Considering practical deployment, we analyze hybrid signature schemes, re-signing, and Merkle-root anchoring-but can these strategies effectively balance security, storage costs, and computational overhead for long-term evidentiary validity?

The Looming Quantum Disruption of Audit Integrity

Contemporary audit log systems, fundamental to maintaining data integrity and accountability, currently depend on cryptographic algorithms like RSA and ECC. These algorithms, while secure against existing computational attacks, are built upon mathematical problems that quantum computers, leveraging principles of superposition and entanglement, are projected to solve efficiently. This vulnerability means that sensitive audit records, detailing critical transactions and system changes, could be decrypted and potentially manipulated by a future adversary possessing sufficient quantum computing power. The implications extend beyond simple data breaches; compromised audit trails could invalidate legal evidence, erode trust in financial reporting, and undermine the very foundation of regulatory compliance. Consequently, the reliance on these classically-based systems presents a significant and growing risk to the trustworthiness of digital records as quantum technology advances.

The accelerating development of quantum computing presents a fundamental challenge to the security of digital records, demanding a transition to post-quantum cryptography. Current encryption standards, such as RSA and ECC, rely on mathematical problems that are easily solved by sufficiently powerful quantum computers, rendering sensitive audit logs vulnerable to decryption and manipulation. Post-quantum cryptography, conversely, focuses on algorithms resistant to both classical and quantum attacks, leveraging different mathematical structures like lattice-based cryptography, multivariate equations, and code-based cryptography. This proactive shift isn’t merely about adopting new algorithms; it requires a comprehensive overhaul of cryptographic infrastructure, including key generation, digital signatures, and encryption protocols, to ensure the continued integrity and trustworthiness of financial transactions, regulatory compliance, and legal documentation in a future where quantum computers are a reality.

The integrity of existing audit trails, crucial for establishing accountability and ensuring legal defensibility, faces a substantial, yet largely unaddressed, risk with the progression of quantum computing. Current digital records, secured by algorithms like RSA and ECC, are anticipated to become vulnerable to attacks from sufficiently powerful quantum computers. This isn’t a future concern; data harvested today, while seemingly secure, could be decrypted and manipulated at a later date, effectively rewriting history and invalidating prior evidence. Consequently, organizations relying on these audit logs for regulatory compliance, fraud detection, or dispute resolution may find their records compromised without detection, leading to significant financial, legal, and reputational damage. The retroactive nature of this threat demands immediate attention and the implementation of quantum-resistant cryptographic solutions to preserve the trustworthiness of digital records over the long term.

Defining the Foundations of Audit Integrity

Q-Audit Integrity is a fundamental security requirement for reliable audit logs, specifically addressing the prevention of fabricated evidence. This notion guarantees that an adversary cannot generate valid-appearing log entries that did not actually occur within the system. Formally, it necessitates that any evidence presented as originating from the audit log must correspond to a genuine event that was legitimately recorded. Achieving Q-Audit Integrity often relies on cryptographic techniques such as digital signatures or Message Authentication Codes (MACs) applied to log entries, binding them to a trusted authority and preventing their unauthorized modification or creation. Without Q-Audit Integrity, the entire audit trail becomes suspect and incapable of providing verifiable proof of system behavior.

Q-Non-Equivocation is a critical security property for audit logs, ensuring that an adversary cannot simultaneously claim both that an event occurred and that it did not. This is achieved by preventing the creation of multiple, conflicting attestations for the same event within the log. Specifically, the security notion requires that for any given event and any valid attestation of that event, it is computationally infeasible for an adversary to produce a different, equally valid attestation contradicting the initial one. Failure to uphold Q-Non-Equivocation compromises the integrity of the audit log, allowing malicious actors to dispute legitimate events or falsely claim events never transpired, thereby undermining trust in the system’s record-keeping capabilities.

Q-Binding is a security property of audit logs that prevents the fraudulent reuse of evidence across multiple attestations. Specifically, it ensures that each unique piece of evidence – such as a digital signature or cryptographic commitment – can only be validly linked to a single event or transaction. This prevents an adversary from falsely inflating the credibility of one event by re-presenting evidence originally generated for a different, potentially unrelated, occurrence. The enforcement of Q-Binding relies on mechanisms that cryptographically ‘consume’ the evidence upon its first valid use, rendering it invalid for any subsequent attestation attempts and maintaining the integrity of the audit trail.

Architecting Trust: Mechanisms for Post-Quantum Audit Logs

A Constant-Size Evidence structure is utilized to standardize the capture of data provenance and integrity information, enabling simplified verification processes. This structure encapsulates essential metadata – including timestamps, data origins, and cryptographic commitments – within a fixed-size container, regardless of the size of the audited data itself. This consistent format facilitates automated processing and reduces the computational overhead associated with verification, as parsers and validators can rely on a predictable data layout. The standardization also supports interoperability between different auditing systems and simplifies the implementation of compliance checks. By decoupling the evidence size from the data size, the system avoids potential denial-of-service vectors related to excessively large audit trails.

Hash-and-Sign construction is a core mechanism for ensuring data integrity in post-quantum systems. This approach involves generating a cryptographic hash of the data to be protected, then digitally signing that hash with a Post-Quantum Cryptographic (PQC) signature scheme. The security of this construction relies on the assumed properties of both the hash function – specifically its collision resistance – and the PQC signature algorithm. Formal security analysis is performed within the Quantum Random Oracle Model (QROM), which provides a rigorous framework for evaluating the resistance of the signature scheme to attacks from quantum computers, given an idealized hash function. The QROM allows for provable security guarantees, demonstrating that a successful attack against the hash-and-sign construction would necessitate breaking the underlying hash function or signature scheme itself.

Merkle-Root Anchoring provides a mechanism for transitioning existing audit logs to a post-quantum secure state without requiring a complete re-logging of all events. This pattern involves constructing a Merkle tree from the existing log data and anchoring the resulting Merkle root with a post-quantum signature. Re-signing legacy evidence then involves periodically re-computing the Merkle root and applying a new post-quantum signature, thereby updating the anchor. Performance testing indicates scalability, with Merkle root computation achievable in under 5 seconds for a corpus containing $10^8$ records, suggesting the feasibility of this approach for large-scale audit log systems.

The system demonstrates a post-quantum (PQ) signature throughput of 5,000 signatures per second under current testing conditions. This performance metric is crucial for evaluating the practicality of re-signing existing, or legacy, audit record to enhance their security against attacks leveraging quantum computing. The throughput calculation is based on the time required to generate and verify PQ signatures for a representative data set, and serves as a benchmark against which alternative PQ signature schemes and hardware acceleration strategies can be compared when considering large-scale migration of audit log infrastructure. Achieving this throughput suggests that re-signing a substantial volume of legacy records within a reasonable timeframe is technically feasible, provided appropriate infrastructure is deployed.

Extending Security and Privacy: Protecting the Audit Pipeline

A robust audit pipeline fundamentally depends on the secure management of cryptographic keys and operations, and a Trusted Execution Environment (TEE) provides that critical foundation. This specialized, isolated environment operates outside the normal operating system, shielding sensitive data – including signing keys – from compromise even if the main system is breached. Within the TEE, cryptographic operations are performed in a hardware-protected enclave, ensuring that keys never leave the secure boundary. This isolation is paramount for maintaining the integrity and authenticity of audit logs, as it prevents malicious actors from forging records or tampering with evidence of system activity. By safeguarding the core cryptographic processes, the TEE not only secures the audit trail but also establishes a high level of trust in the data it contains, essential for compliance, forensics, and overall system security.

Hybrid signatures represent a pragmatic approach to the looming threat of quantum computing to current cryptographic systems. This technique combines traditional, widely-trusted digital signature algorithms – such as RSA or ECDSA – with emerging post-quantum algorithms, like those based on lattices or codes. By generating a signature that incorporates both, the system remains secure even if quantum computers capable of breaking classical cryptography become a reality. Critically, this allows organizations to transition to post-quantum security at their own pace, avoiding the immediate and costly disruption of replacing all existing cryptographic infrastructure. The hybrid approach ensures interoperability with legacy systems, as the classical component of the signature remains verifiable by existing tools, while simultaneously building a foundation for long-term security against quantum attacks. This phased implementation minimizes risk and maximizes the utility of existing investments in security infrastructure.

A Trusted Execution Environment (TEE) extends beyond simply safeguarding audit logs; it fundamentally alters how sensitive data is handled within them. By performing computations on encrypted data inside the secure enclave of the TEE, techniques like Differential Privacy become practical. This approach introduces carefully calibrated noise to the data before it’s logged, ensuring individual records remain confidential while still allowing for meaningful aggregate analysis. The TEE guarantees that this noise addition is performed correctly and cannot be bypassed, preserving the privacy promises even if the audit logs themselves are compromised. Consequently, organizations can leverage the benefits of audit trails – accountability and transparency – without inadvertently exposing private user information or proprietary data, fostering both trust and compliance.

A practical concern with enhancing audit log security through re-signing is the computational overhead involved, particularly when dealing with substantial data volumes. Recent evaluations indicate that re-signing approximately 10 million audit records on a single processor core requires roughly 34 minutes. This timeframe demonstrates the operational feasibility of migrating existing audit logs to newer, more secure cryptographic schemes without necessitating prolonged downtime or disruptive system outages. The relatively swift processing speed suggests that organizations can implement these security enhancements as part of routine maintenance or scheduled updates, minimizing the impact on ongoing operations and bolstering the overall integrity of their audit trails.

The pursuit of robust evidence structures, as detailed in the study, echoes a fundamental principle of systemic resilience. The paper rightly emphasizes formal security definitions against quantum adversaries, recognizing that vulnerabilities often lie not in individual components, but in the boundaries between them. As Ada Lovelace observed, “The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform.” This perfectly encapsulates the need for meticulously defined migration patterns and cryptographic protocols; the system’s security is wholly dependent on the clarity and integrity of the instructions – and the structures upholding them – given to it. Without precise definition, even the most advanced system is susceptible to unforeseen weaknesses.

Beyond the Horizon

The pursuit of quantum-resistant audit trails, as outlined in this work, quickly reveals a fundamental question: what, precisely, are these trails meant to preserve? Too often, the focus remains on cryptographic robustness-a necessary, but insufficient, condition. A truly resilient system demands clarity regarding the evidentiary value of each logged event. The structure dictates behavior, and a poorly designed evidence structure, even one fortified against quantum decryption, will yield data of questionable integrity. Simplicity is not minimalism; it’s the discipline of distinguishing the essential from the accidental.

Future work must move beyond solely addressing the threat of quantum adversaries. The migration patterns for existing logs-a pragmatic concern-highlight a deeper problem. Legacy systems were rarely designed with forensic rigor in mind. Retrofitting security is akin to bolting armor onto a ship already at sea. The challenge lies not merely in securing the data, but in establishing a verifiable chain of provenance for information generated by systems that lacked such considerations from the outset.

Ultimately, this field will be defined not by the complexity of its cryptography, but by the elegance of its data structures. The goal isn’t simply to log everything, but to log only what matters, and to do so in a manner that ensures its enduring verifiability-regardless of the computational landscape. One suspects the most fruitful advances will emerge from a renewed focus on formal methods and a critical reassessment of what constitutes ‘evidence’ in the age of increasingly autonomous systems.

Original article: https://arxiv.org/pdf/2512.00110.pdf

Contact the author: https://www.linkedin.com/in/avetisyan/

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2025-12-02 08:23