As organisations generate, exchange and retain increasing volumes of sensitive data on a daily basis, ensuring the authenticity and integrity of that information has become a major issue. Businesses must now rely on a reliable digital trust infrastructure to secure their documents, automate their processes and meet regulatory requirements, in particular those arising from the European eIDAS Regulation.
At the centre of this infrastructure lies a component that is often little known to the general public but indispensable for professionals in cybersecurity, compliance and records management: the HSM (Hardware Security Module). Acting as a cryptographic vault, the HSM protects private keys, underpins electronic signatures and electronic seals, and secures qualified timestamping as well as evidential electronic archiving.
Understanding the role of an HSM, its technical operation and its position within the digital evidence chain is necessary in order to implement processes that are reliable, auditable and legally enforceable. This article provides a comprehensive overview of the HSM, its use cases and the standards governing its deployment.
Table of content
- What is an HSM (Hardware Security Module)?
- How does an HSM operate?
- What is the link between HSMs and timestamping?
- Why do HSMs and timestamping strengthen data security within organisations?
- Different types of HSMs: cloud HSM, on-premise HSM, managed HSM
- Why rely on Evidency’s Qualified Timestamping services?
Key points to remember about HSMs:
- An HSM is a hardware device dedicated to the secure protection, generation and management of cryptographic keys.
- It provides the technical foundation for digital trust services: qualified timestamping, electronic seals, electronic signatures and evidential electronic archiving.
- When integrated into trust services, it ensures the integrity, authenticity and immutability of data in accordance with eIDAS standards.
What is an HSM (Hardware Security Module)?
It is one of the most critical components of an organisation’s trust infrastructure.
Definition and core principles
A Hardware Security Module (HSM) is a specialised hardware device designed to generate, protect and use cryptographic keys within a fully secure environment. Unlike a purely software-based solution, an HSM relies on a dedicated hardware architecture that incorporates tamper-resistance mechanisms and safeguards for cryptographic keys. These mechanisms may be subject to security certifications and audits in accordance with applicable standards.
HSMs are used by banks, trust service providers, public authorities, SaaS vendors, cloud service providers and, more generally, by any organisation handling digital evidence or sensitive data.
Why use an HSM rather than a software-based solution?
Purely software-based solutions provide limited security, as private keys may potentially be copied, transferred or intercepted.
With an HSM:
- cryptographic operations are performed within the HSM itself, so that private keys never leave the device in an exploitable form,
- the hardware is certified (FIPS 140-2/3, Common Criteria, etc.),
- key management activities are logged and subject to control,
- cryptographic operations are isolated from the rest of the system.
Through certified hardware protection and the complete isolation of cryptographic keys, an HSM delivers a level of security required to ensure the reliability and regulatory compliance of qualified trust services.
Why do organisations use HSMs?
HSMs are used to secure sensitive digital operations. They support the creation of reliable electronic signatures, strengthen strong user authentication mechanisms and ensure the encryption of sensitive data. By protecting cryptographic keys within a certified environment, they also assist organisations in meeting regulatory requirements, in particular the eIDAS Regulation for qualified electronic signatures and seals, as well as the GDPR with respect to the protection of personal data.
How does an HSM operate?
The HSM plays a strategic role in all cryptographic operations by ensuring the security, confidentiality and integrity of the keys used to sign, timestamp or apply electronic seals to data.
Generation and storage of cryptographic keys
The primary function of an HSM is the secure generation of cryptographic keys used in signature, sealing, timestamping and encryption processes. These keys are created within a controlled hardware environment, preventing any extraction or duplication.
The HSM operates as a digital vault, inaccessible both physically and logically, including to system administrators.
Execution of cryptographic operations
The HSM directly performs all essential cryptographic operations, including digital signing and electronic sealing, signature verification, encryption and decryption, secure timestamping, as well as the generation of certified random numbers (RNGs). In practical terms, private keys never leave the HSM; only the cryptographic results are released from the module.
Securing the chain of trust
Within an eIDAS-compliant digital evidence framework, the HSM provides the foundation that ensures:
- data integrity (protection against alteration),
- authenticity (certified origin),
- non-repudiation (legally admissible evidence),
- traceability of critical operations.
What is the link between HSMs and timestamping?
Timestamping plays a central role in digital evidence, as it makes it possible to demonstrate that a document or an event existed at a specific point in time and has not been altered. Whether simple, electronic or qualified, timestamping relies on an HSM to secure the cryptographic keys used to sign the timestamp token and to ensure the reliability, integrity and traceability of the operation.
The role of the HSM in timestamping
Timestamping is based on the concept of a digital fingerprint, a unique cryptographic digest of a document or data set. This fingerprint makes it possible to verify that the content has not been modified, thereby providing proof of integrity. Timestamping also establishes proof of existence at a given date and time, demonstrating that a document existed at a precise moment. When issued by a qualified provider in compliance with eIDAS, it carries recognised legal effect and may be relied upon as evidence in the context of a dispute or an audit.
Why timestamping must be secured by an HSM?
To ensure reliability, the signing keys used for timestamp tokens are stored within a certified HSM. Without an HSM, timestamping mechanisms would be more exposed to manipulation, which could undermine the integrity of timestamps and the evidential value of the documents concerned. The HSM securely binds the document’s digital fingerprint to the date and time associated with the timestamping request, thereby supporting the integrity and reliability of timestamp tokens.
Evidency’s Timestamping services rely on established cryptographic principles and secure infrastructures that comply with European standards.
Why do HSMs and timestamping strengthen data security within organisations?
By combining reliable timestamping with a certified HSM, organisations establish a trusted chain that protects data throughout its entire lifecycle. This approach secures sensitive information, strengthens the reliability of digital evidence and enables organisations to meet increasing requirements in terms of compliance and data governance.
Protection against falsification and deepfakes
Timestamping secured by an HSM makes it possible to fix a content’s digital fingerprint at a given point in time, rendering any subsequent modification immediately detectable. In an environment where digital falsification and deepfakes are increasingly prevalent, this ability to demonstrate the integrity and prior existence of a document, multimedia file or technical log provides a strong safeguard against fraud and the manipulation of information.
Comprehensive traceability and proof of integrity
The combination of an HSM and timestamping ensures end-to-end traceability of critical operations, from data creation through to long-term retention. Each action is linked to a cryptographic fingerprint and a certified date, making it possible to demonstrate that the information has not been altered. This level of traceability is necessary for audits, internal controls and the management of digital risks.
Legal admissibility and regulatory compliance
The use of an HSM in conjunction with timestamping services aligned with eIDAS requirements ensures the legal admissibility of digital evidence. This compliance is particularly strategic for public and private organisations subject to stringent obligations relating to security, data protection and legal accountability, especially in regulated sectors or environments where trust is a determining factor.
Different types of HSMs: cloud HSM, on-premise HSM, managed HSM
The market now offers several approaches, enabling organisations to align security arrangements with their operational requirements.
| Type of HSM | Description | Advantages | Limitations |
| On-premise HSM | Physically installed within the organisation’s premises. | Full control, no reliance on cloud infrastructure. | High management, maintenance and cost burden. |
| Cloud HSM | HSM hosted in the cloud, often certified and accessible via API. | Flexibility, high availability, straightforward integration. | Dependence on a cloud provider. Stricter regulatory constraints for certain sectors (some jurisdictions require a local HSM for specific operations). |
| Managed HSM | HSM infrastructure operated by a trust service provider on behalf of clients (cloud or on-premise). | Reduced operational burden for the organisation; access to a certified HSM without in-house expertise. | Reliance on an external service provider. |
Why rely on Evidency’s Qualified Timestamping services?
Evidency’s Qualified Timestamping services are built on a highly secure infrastructure designed to meet stringent digital trust requirements. Timestamping operations rely on certified components, including HSMs that comply with recognised security standards, ensuring the protection of cryptographic keys and the integrity of issued tokens.
Evidency’s Timestamping services are fully aligned with European regulations, in particular the eIDAS Regulation and the ETSI standards applicable to Qualified Timestamping authorities. This alignment ensures recognised legal effect for the evidence produced, suitable for use in audit, supervisory or contentious proceedings.
Designed for seamless integration into existing environments, Evidency’s services are accessible via API and fit naturally within automated processes. This approach enables organisations to industrialise the generation of evidence without technical complexity or disruption to established business workflows.
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