Why hardware security modules matter

Hardware security modules are physical computing devices specifically designed to protect cryptographic keys and perform cryptographic operations within a secure, isolated environment. They serve as trust anchors for your PKI environment, ensuring that private keys and digital keys remain within secure confines and are never exposed to unauthorised access.

Without proper protection, cryptographic keys are vulnerable. Software-based key storage increases the attack surface and exposes sensitive information to theft or compromise. Hardware security modules work by providing tamper-resistant and tamper-evident protection, ensuring keys used for encryption, digital signatures, and authentication remain secure throughout their lifecycle.

As organisations adopt cloud services, support multiple clouds, and manage critical infrastructure, the need for robust data protection and data security increases. Hardware security modules HSMs provide the highest security standards for securing data across on-premise and cloud environments. They enable secure generation, key storage, and management of cryptographic keys whilst meeting compliance requirements including PCI DSS, Common Criteria, and industry standards.

For financial transactions, code signing, digital signing, and protection of intellectual property, hardware security modules ensure cryptographic processes occur within intrusion-resistant hardware that meets stringent security requirements. Many organisations now adopt HSM as a service models or subscription-based offerings that provide specialized HSMs with the same level of protection as on-premise deployments, but with features suited to cloud service providers and multiple form factors.

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Our HSM Services

Hardware security modules are critical to the integrity and security of your cryptographic infrastructure. At Unsung, our vendor-certified consultants specialise in designing, deploying, and managing HSM solutions across complex PKI environments.

We've worked with government and private sector organisations to integrate hardware security modules into secure, compliant, and scalable PKI architectures, whether on-premises or cloud-based. We support a wide range of HSM vendors and help clients navigate both regulatory and operational demands.

Our approach balances robust technical implementation with business alignment, ensuring your HSM strategy meets both security standards and organisational goals whilst protecting cryptographic keys and sensitive data.

Public Key Infrastructure is the backbone of secure digital communication. It enables trusted transactions, protects sensitive data, and verifies identities across networks. From securing online banking and e-commerce to enabling encrypted corporate communications, PKI is fundamental to the trust framework of the internet and private networks.

For many organisations, understanding PKI is the first step towards implementing strong security practices. As cyber threats grow in sophistication and regulatory requirements become more demanding, Public Key Infrastructure provides a proven and scalable framework for protecting information and ensuring that only authorised parties can access systems and services.

What is Public Key Infrastructure?

Public Key Infrastructure PKI is a framework of technologies, policies, and procedures that manage the creation, distribution, use, and revocation of digital certificates. These certificates act as digital passports, confirming that an entity (whether a person, device, or application) is legitimate and trustworthy.

At the heart of PKI are Certificate Authorities (CAs), which issue certificates after verifying the identity of the requesting entity. Working alongside them are Registration Authorities (RAs), which handle the identity verification process on behalf of the certificate authority, ensuring that only authorised and verified requests result in certificate issuance.

A typical PKI ecosystem also includes:

Public and private key pairs
The cryptographic foundation enabling secure encryption and digital signatures. The public key is available to anyone to encrypt data or verify a digital signature, whilst the private key is kept securely by the owner to decrypt data or create a digital signature.

Certificate repositories
Centralised locations for storing and retrieving issued certificates and their revocation status. These repositories enable web browsers, operating systems, and other systems to verify certificates issued by trusted CAs.

Certificate Revocation Lists and Online Certificate Status Protocol services
Mechanisms to check whether a certificate is still valid or has been revoked. The Online Certificate Status Protocol provides real-time validation, whilst CRLs offer periodic updates on revocation status.

Together, these key components create a trust framework that allows secure communication between parties who may never have interacted before, without needing to directly trust one another or share a pre-existing secret.

How PKI works with asymmetric cryptography

Public Key Infrastructure uses asymmetric cryptography, which involves a mathematically linked pair of keys (a public key and a private key) to secure communication. This asymmetric encryption differs from symmetric encryption, which uses one key for both encryption and decryption.

With asymmetric cryptography:

Public key encryption
The public key encrypts data that only the corresponding private key can decrypt. This enables anyone to send an encrypted message to the key holder without requiring a pre-shared secret.

Digital signatures
The private key creates a digital signature that the public key can verify. This proves the identity of the sender and ensures data integrity, confirming that the message has not been altered.

When you connect to a website over HTTPS, your browser and the web server perform a TLS handshake. This process:

• Verifies the server's identity using its SSL certificate issued by a trusted certificate authority CA
• Negotiates encryption settings to protect the session
• Establishes a secure communication channel so that any data exchanged remains confidential and tamper-proof

The browser checks the certificate chain, validating that the SSL certificate was issued by a trusted CA (or intermediate CA linked to a root CA) and that the certificate is within its validity period. This mechanism ensures that sensitive information (such as login credentials, credit card information, or personal data) cannot be intercepted or altered during transmission.

Real-world importance of digital certificates

PKI is not an abstract or niche technology. It underpins the trust in many of the services people use daily. Common applications include:

E-commerce and internet security
Protecting payment transactions and customer details. Digital certificates secure access to online services and protect credit card information during financial transactions.

Government and citizen communications
Securing online tax submissions, benefit applications, and digital services. Public Key Infrastructure PKI enables governments to authenticate users and protect sensitive information.

Secure email and document signing
Ensuring authenticity and preventing tampering in business communications. Digital signatures verify identity and maintain data integrity across electronic documents.

Authentication for applications and APIs
Controlling secure access to sensitive systems and enabling machine-to-machine trust. Certificates issued by CAs authenticate users and devices, ensuring only authorised entities can access protected resources.

Challenges without Public Key Infrastructure

Without PKI, organisations risk operating in an environment where identities cannot be reliably verified and communication is vulnerable. This can lead to:

Higher susceptibility to cyber attacks
Including man-in-the-middle attacks, phishing, and spoofing. Without trusted certificate authorities to verify identity, attackers can more easily impersonate legitimate entities.

Exposure of sensitive data
Potentially resulting in data breaches and regulatory penalties. Without encryption to protect data in transit, sensitive information becomes vulnerable to interception.

Erosion of digital trust
Customers, partners, and regulators lose confidence when services are not demonstrably secure. Trust frameworks established through PKI instill trust in digital interactions.

PKI and Certificate Lifecycle Management

Whilst Public Key Infrastructure establishes the foundation of digital trust by issuing and managing digital certificates, it does not inherently address the operational challenges of keeping those certificates current. This is where Certificate Lifecycle Management plays a vital role.

CLM solutions automate the discovery, monitoring, renewal, and revocation of certificates across complex environments. They provide real-time visibility into certificate inventories, enforce certificate policy requirements, and ensure that certificates are replaced before expiry or security issues occur.

Certificate management tools track CA certificates, manage digital certificates across web servers and systems, identify self-signed certificates that bypass the trust store, and monitor the distinguished name and validity period of certificates issued throughout the organisation.

In practice, PKI and CLM are most effective when deployed together. Public Key Infrastructure creates and governs the trust model, whilst CLM ensures that trust is continuously maintained throughout the certificate lifecycle, reducing the risk of outages, security incidents, or compliance failures.

Understanding PKI for secure communications

Understanding PKI is essential for any organisation operating in a digital environment. It is not just a technical standard but a framework for establishing and maintaining digital trust in online interactions. Without it, secure communications, data integrity, and identity verification cannot be guaranteed.

When PKI is paired with effective certificate lifecycle management, organisations gain both the foundation for secure communication and the operational capability to keep that trust intact. This combination protects sensitive data, supports compliance with regulatory requirements, and ensures services remain secure and reliable in an ever-evolving threat landscape.

Worth noting: the distinction between trusted certificate authorities, intermediate CAs, and root CAs matters. Web browsers and operating systems maintain trust stores containing root CA certificates. The certificate issuer must be part of this chain of trust for the browser to verify the certificate and establish a secure connection. Self-signed certificates, which bypass this trust framework, should be used cautiously and only in controlled environments where the issuing CA can be directly trusted.

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