Skip to main content

What is a Hardware Security Module (HSM)?

Hardware security modules (HSMs) are hardened, tamper-resistant hardware devices that secure cryptographic processes by generating, protecting, and managing keys used for encrypting and decrypting data and creating digital signatures and certificates. HSMs are tested, validated and certified to the highest security standards including FIPS 140-2 and Common Criteria. Entrust is a leading global provider of HSMs with the nShield General Purpose HSM product family.

HSMs enable organizations to:

  • Meet and exceed established and emerging regulatory standards for cybersecurity, including GDPR, eIDAS, PCI DSS, HIPAA, etc
  • Achieve higher levels of data security and trust
  • Maintain high service levels and business agility

What is HSM as a service or Cloud HSM?

HSM as a service is a subscription-based offering where customers can use a hardware security module in the cloud to generate, access, and protect their cryptographic key material, separately from sensitive data. The service offering typically provides the same level of protection as an on-premises deployment, while enabling more flexibility. Customers can transfer CapEx to OpEx, enabling them to only pay for the services they need, when they need them.

nShield as a Service uses dedicated FIPS 140-2 Level 3 certified nShield HSMs. The offering delivers the same full set of features and functionality as on-premise nShield HSMs, combined with the benefits of a cloud service deployment. This allows customers to fulfill either their cloud first objectives or deploy a mix of on-premise and as-a-Service HSMs, with maintenance of the as-a-Service appliances performed by the experts at Entrust.

Why should I use an HSM?

Cryptographic operations like encryption and digital signing are worthless if the private keys they use are not well protected. Attackers today have grown much more sophisticated in their ability to locate private keys that are stored or are in use. HSMs are the gold standard for protection of private keys and associated cryptographic operations, and enforce the policy defined by the using organization for users and applications that can access those keys. HSMs can be used with many different types of applications that perform encryption or digital signing. The top 10 use cases for HSMs, from the 2021 Ponemon Global Encryption Trends Study (May 2021), are shown in the figure below.

top 10 HSM use cases for 2021 infographic

What value does an HSM provide?

HSMs enhance and extend the security of a wide range of applications that perform encryption and digital signing. The table below describes the added value of HSMs for a set of the most common use cases.

Use Case

Cloud and Containers/Kubernetes
Public Key Infrastructure (PKI)
Privileged Access and Secrets Management
Encryption and Tokenization
Key Management
Digital Signing and Code Signing
TLS/SSL applications (ADCs, Firewalls, etc.)
Identity and Authentication

Value of HSM to Use Case

Maintain control of keys and data in the cloud; secure containerized applications
Protect critical PKI root and CA signing keys
Address insider threats and simplify access to secrets for DevOps
Enhance encryption key protection for data in transit and storage
Enforce key management policy across multiple clouds and applications
Protect keys that ensure software integrity and enable legally binding transactions
Secure master TLS/SSL encryption keys
Create trusted identity credentials
Protect the keys that create and sign payment credentials

What is a Root of Trust?

Root of Trust (RoT) is a source that can always be trusted within a cryptographic system. Because cryptographic security is dependent on keys to encrypt and decrypt data and perform functions such as generating digital signatures and verifying signatures, RoT schemes generally include a hardened hardware module. A principal example is the hardware security module (HSM) which generates and protects keys and performs cryptographic functions within its secure environment.

Because this module is for all intents and purposes inaccessible outside the computer ecosystem, that ecosystem can trust the keys and other cryptographic information it receives from the root of trust module to be authentic and authorized. This is particularly important as the Internet of Things (IoT) proliferates, because to avoid being hacked, components of computing ecosystems need a way to determine information they receive is authentic. The RoT safeguards the security of data and applications and helps to build trust in the overall ecosystem.

RoT is a critical component of public key infrastructures (PKIs) to generate and protect root and certificate authority keys; code signing to ensure software remains secure, unaltered and authentic; and creating digital certificates and machine identities for credentialing and authenticating proprietary electronic devices for IoT applications and other network deployments.

What is random number generation?

Random number generation (RNG) refers to the random numbers created by an algorithm or device. It is important that cryptographic keys are created using a certified source of random numbers, which is a challenging problem for software-based systems.

When the source of entropy for a random number generator is derived from software-based measurements, it cannot be guaranteed that the entropy will not be predictable, or able to be influenced. An HSM uses a hardware-based source of entropy for its RNG that has been verified to provide a good source of entropy in all normal operating conditions. This is important for use cases like BYOK (Bring Your Own Key), which allows users to create and manage keys that they upload to cloud service providers.