Machine Identity

When you log in to an online service, you identify yourself with a username and password. The service checks whether you really are you. The exact same problem exists between programs: a payment app must prove to the bank that it really is that app. To do this, every program, every device, and every server gets its own digital credential. This credential is called a machine identity. It doesn’t consist of a password to remember, but of long strings of numbers managed by a computer.

Why there are more credentials for software than for humans

A typical company might employ around 5,000 people. At the same time, hundreds of thousands of small programs are running there, constantly talking to one another. Security firms estimate that there are now several dozen machine accounts for every single human account. Each of these accounts is a potential entry point for attackers. Whoever steals such a credential can pose as a trustworthy program.

Humans usually notice when their account is taken over. A program notices nothing at all. It simply keeps working, even if its access credentials were copied long ago. That’s why stolen machine identities are considered especially dangerous. Several major attacks in recent years began exactly this way: with a key that was accidentally left publicly exposed on the internet.

The topic is being freshly fueled by AI systems that carry out tasks autonomously. Such programs book trips, write emails, or access databases. They too need a credential, one with precisely defined permissions. Otherwise, a misdirected program can cause damage that no one intended.

Certificates, keys, and tokens

The most common form is the digital certificate. You can think of it as a certified ID card. A trustworthy authority, the certificate authority, confirms in it: this server really does belong to this address. Your browser checks such certificates every time you visit a webpage. The little lock icon in the address bar shows that the check succeeded.

There are also API keys and tokens. An API key is a long string of characters that a program sends along with every request. A token is a time-limited entry ticket that expires after minutes or hours. Short lifespans are intentional: a stolen ticket quickly becomes worthless. Certificates also expire, often after 90 days or less.

This is exactly where the real work comes in. Every credential must be renewed, distributed, and eventually revoked in time. With hundreds of thousands of identities, this can no longer be done by hand. Specialized software takes over this lifecycle automatically. If a team forgets a renewal, the service goes down, even though nothing is technically broken.

From the browser lock icon to the cloud bill

You encounter machine identities every day without noticing. Every encrypted website uses one of these certificates. Your banking app checks whether it’s really talking to the bank’s server. Even your phone identifies itself to the mobile network, via the SIM card.

In business news, the term usually comes up in two contexts. First, in security incidents, when attackers gained entry via expired or leaked keys. Second, as a growth market: providers like CyberArk, Venafi, or HashiCorp make money managing these credentials. CyberArk’s acquisition of Venafi in 2024 was seen as proof of how important this field has become.

A common misconception is that machine identity is just another word for password. The difference lies in scale and speed. A human rarely changes their password, while a cloud system creates and deletes identities every second. It is precisely this dynamic that makes the topic so demanding.