Encrypt IoT

Security    Clarity    No-BS

E4 — MQTT encryption done right

E4 is the first and only end-to-end encryption solution for MQTT, the most popular machine-to-machine protocol.

We solve the hardest problem of MQTT encryption: key management. With E4, you can remotely manage keys of millions of devices with no performance hit (no extra network round-trip, 24-byte per-packet overhead).

E4 is compatible with leading IoT cloud platforms: AWS IoT Core , Azure IoT Hub, and Google Cloud IoT Core.

Seamless integration

  • Compact software library running between transport and business layers
  • Server deployed as containerized application or virtual appliance
  • No change to the broker required

End-to-end security

  • All messages are encrypted, protected against replay and spoofing
  • Protects against compromised broker servers and infrastructure
  • Safe against quantum computing

Key management server

  • Zero-touch automation of key rotation policies for 1-to-1 or N-to-M topologies
  • Live analytics, anomaly detection, and monitoring service
  • Web UI, REST, and gRPC interfaces


We want to make strong encryption the default for IoT and machine-to-machine communications.

We rely on our experience building secure communication software and industrial cryptography systems. Security protocols and algorithms that we designed are now deployed in millions of devices, and some have become international standards.

Teserakt AG is an international company incorporated in 2018 in Lausanne, Switzerland.
Our core team is in Lausanne, and we work with people based in Croatia, Germany, and UK.

Current customers include companies in diverse sectors, such as aerospace and law enforcement technology.

Find us on GitHub, LinkedIn, Twitter. Email us at [email protected], we'd be happy to show you a demo.


Secure software and cryptography is our core expertise—we designed algorithms now used in the Linux kernel and Apple devices.

A security product should improve your security posture, not diminish it through vulnerable applications and the illusion of security.


No bells and whistles; we are not ashamed to say that our solution is simple and only supports a handful of parameters.

A large part of our software is written in Go, which helps maintaining a clear codebase and lean architecture.

"Complexity is the enemy of security" is cliché but true.


Many security companies prioritize marketing over engineering and security. We don't.

Instead of superlatives and stock photos, we prefer technical facts and convincing proof-of-concept deployments.

No "military-grade" here, no claims of using "AI" if we don't.


You can download the following documents:

Our open-source repositories:

  • sha3-avr: Implementation of the SHA-3 hash functions for 8-bit AVR

To learn more about MQTT and its security, we recommend the following external resources: