B-Secur has developed a biometric technology that uses an individual's heartbeat pattern, or electrocardiogram (ECG), to authenticate their identity.
The investors are Accelerated Digital Ventures (ADV) and Kernel Capital.
The firm said the money would allow it to "grow significantly" in the next year.
B-Secur said it is currently working in the UK, Ireland and the US "to respond to customers across many sectors" including automotive, financial services and access control.
Biometrics, like fingerprint and iris recognition, are an increasingly common security feature on devices like mobile phones.
However, there are questions about how secure those features are.
For example, German hackers defeated the iris-recognition feature in Samsung's new Galaxy S8 smartphone using an artificial eye.
Samsung said that required "a rare combination of circumstances" to pull off, including possession of a high-resolution image of the smartphone owner's iris.
B-Secur say that as "an internal biometric", ECG authentication can minimise hacking or spoofing risks.
A Belfast-based cybersecurity firm which uses heartbeats to check identity has raised fresh backing of £3.5m from two investment funds.