What is a Machine Identity?

What is a machine identity?

A machine identity is a digital identity assigned to a non-human entity — such as a computer, server, application, virtual machine, container, or IoT device — that allows it to securely communicate, authenticate, and perform tasks over a network.

Why Machine Identities Matter

Just like people use usernames and passwords, machines need identities to:

• Authenticate to other systems and services
• Encrypt data for confidentiality
• Sign messages or code to ensure integrity
• Establish trust between services in automated workflows or cloud environments

In short: machine identities are critical for securing machine-to-machine (M2M) communication in modern IT environments.

Types of Machine Identities

Some common forms include:

Type	Example Use Case
SSL/TLS Certificates	Identify and secure websites and APIs
SSH Keys	Grant remote access to servers or devices
API Keys/Tokens	Authenticate software apps to services
X.509 Certificates	Secure connections between microservices
Cloud Instance	AWS IAM roles, Azure managed identities

Where They Are Used

• Enterprise Networks – Between devices like printers, servers, and routers
• Cloud Environments – Between containers, VMs, and cloud-native services
• IoT Devices – Authenticating sensors, cameras, or industrial equipment
• DevOps Pipelines – Securely connecting tools and services (e.g., CI/CD)

Why Managing Machine Identities Is Critical

Poor machine identity management can lead to:

• Data breaches from expired or stolen certificates
• Unauthorized access due to unrotated keys or tokens
• Downtime from services failing to authenticate
• Compliance violations (e.g., PCI DSS, HIPAA)

Given the explosion of machines in modern IT (especially in cloud and hybrid environments), machine identity management is now a key area of cybersecurity — much like identity and access management (IAM) is for people.

How many machine identities for every human identity?

The ratio of machine identities to human identities is rapidly growing — and in many environments, machine identities outnumber human ones by a factor of 10:1 or more.

These numbers are rising fast due to the explosion in:

• Microservices
• Containers
• Serverless functions
• APIs and integrations
• IoT devices and edge computing

What Counts as a Machine Identity?

Every time one of these is spun up or configured, it usually requires a unique credential or certificate:

• VM or container instance
• Kubernetes pod or service account
• API client or service
• IoT device
• Automation bot
• CI/CD pipeline component

Each needs a secure digital identity to authenticate, encrypt, or authorize actions.

Why This Matters

1. Security Risk

• More identities mean more attack surface.
• Unmanaged or forgotten machine identities (e.g., expired certs, stale keys) are a common source of breaches.

2. Visibility Challenges

• Human identities are usually linked to HR systems and easily tracked.
• Machine identities are ephemeral, decentralized, and hard to inventory — especially in the cloud.

3. Governance Needs

• Organizations must now apply IAM best practices to machine identities: rotation, revocation, least privilege, auditing, etc.

Industry Trends

• According to Gartner and Venafi:
  “Machine identities are growing at more than twice the rate of human identities.”
• Some large enterprises already report over 100,000+ machine identities, vs. just a few thousand human users.

What is the difference between machine identity and non human identity?

While the terms machine identity and non-human identity (NHI) are often used interchangeably, they aren’t always the same. Here’s a breakdown of their differences and overlap:

Definitions:

Machine Identity

A subset of non-human identities tied explicitly to:

• Physical or virtual devices
• Software components
• Systems or workloads

Machine identities are used to authenticate and secure machine-to-machine communications (e.g., a web server talking to a database).

Examples:

• TLS certificates for servers
• SSH keys for accessing remote machines
• API tokens for a backend service

Non-Human Identity (NHI)

A broader term that includes all identities not tied to a person, including:

• Machines
• Service accounts
• Automation scripts
• Bots
• Applications
• CI/CD pipelines

These identities can perform actions, access resources, or communicate, just like a human, but are managed by the system.

Examples:

• An Azure AD service principal used by an automation script
• A GitHub Actions identity deploying code
• A bot account that responds in Slack

How They Relate

Think of machine identities as one kind of non-human identity. All machine identities are non-human identities, but not all non-human identities are machines.

 Security Implications

• Machine identities are critical for device-to-device trust and data encryption.
• Non-human identities require access control and privilege management, just like human users — especially in cloud and automation-heavy environments.

What is the difference between IdM and IAM?

The terms IdM (Identity Management) and IAM (Identity and Access Management) are closely related and often used interchangeably, but they have important distinctions in scope and focus. Here’s a clear breakdown:

Definition & Scope

IdM – Identity Management

• Focuses on managing identities (primarily who someone or something is).
• Includes the creation, maintenance, and deletion of digital identities over time.
• Deals mostly with attributes and lifecycle of identities.

Key Functions:

• User provisioning/deprovisioning
• Managing identity attributes (e.g., job title, department)
• Identity repositories (LDAP directories, databases)
• Password management and reset flows

Think of IdM as the foundation: It defines and manages the identity itself.

 IAM – Identity and Access Management

• Encompasses IdM but goes further: It combines identity management with access control.
• Focuses on what an identity can do — what resources it can access, and under what conditions.
• A security framework for enforcing policies, authentication, and authorization.

Key Functions (includes all of IdM, plus):

• Authentication (e.g., username/password, MFA)
• Authorization (e.g., RBAC, ABAC, least privilege)
• Single Sign-On (SSO)
• Federated identity / identity federation
• Policy enforcement
• Auditing and access reviews

IAM answers: “Who are you, and what are you allowed to do?”

Relationship Between the Two

• IdM is a subset of IAM.
• You need identity management to know who the users and systems are before you can control what they can access through IAM.
• In practice, IAM solutions today include robust IdM features, so the lines can blur.