STCP

Secure Transport Protocol designed for embedded systems, Linux environments, IoT infrastructure and industrial communication systems.

Linux Zephyr RTOS MQTT LTE-M AES-256-GCM ECDH
STCP Architecture

Why STCP?

Modern Encryption

Uses ECDH key exchange and AES-256-GCM authenticated encryption for secure communication.

Embedded Friendly

Designed for embedded devices, industrial systems, LTE-M products and IoT deployments.

Linux Integration

Supports both Linux userspace and Linux kernel development environments.

MQTT Support

Native integration with MQTT transport layers and message broker infrastructures.

Low Latency

Designed to minimize connection overhead and maximize communication efficiency.

Open Source

Open development model with source code available through GitHub.

Performance Comparison

STCP v2 has been benchmarked against a comparable TLS implementation using the same application workload: 5 concurrent clients and 500 MB of application data transferred through an echo-style test.

Application Throughput

Higher is better

STCP v2 142.5 MB/s
TLS 57.6 MB/s

Total Echo Traffic

Application traffic counted in both directions

STCP v2 285.0 MB/s
TLS 115.2 MB/s

Completion Time

Lower is better

STCP v2 3.51 s
TLS 8.68 s
5 Concurrent clients
500 MB Application payload
~2.47x Throughput vs TLS in this benchmark

Benchmark results represent the current STCP v2 development version and the current TLS comparison runner. Results may change as both implementations evolve.

Current Development Status

Native BSD socket backend
Rust implementation
AES-256-GCM encrypted transport
X25519 key exchange
Multi-client stress testing
MQTT integration
Zephyr RTOS support
Linux userspace support
Linux kernel module research
Commercial SDK packaging

Roadmap

Protocol Design

Secure framing, encrypted payload handling and key exchange model.

Rust + Native Socket Implementation

Low-level BSD socket based STCP v2 implementation for Linux userspace.

MQTT and Zephyr Demonstration

Verified MQTT-over-STCP communication with Zephyr RTOS and LTE-M hardware.

Performance Optimization

Multi-client throughput testing and STCP versus TLS benchmark comparisons.

Kernel Integration and SDK Packaging

Next development phase focuses on Linux kernel integration research and reusable commercial SDK packaging.

STCP + MQTT Demonstration

STCP MQTT Diagram

STCP has been successfully integrated with MQTT and tested over LTE-M networks using Nordic Semiconductor hardware and Zephyr RTOS.

Designed For

Industrial Automation

Secure communication between controllers, gateways and backend services.

Remote Monitoring

Secure telemetry and device management across distributed infrastructures.

IoT Platforms

Lightweight encrypted transport for large-scale IoT deployments.

Embedded Linux

Secure transport for custom Linux devices and edge computing solutions.

About The Project

STCP (Secure Transport Protocol) is a lightweight encrypted transport protocol developed for modern embedded systems, Linux platforms, industrial communication and IoT infrastructure.


The project is developed by Paxsudos IT, a Finnish technology company focused on software engineering, embedded systems, secure communication technologies and infrastructure solutions.


Source code:


https://github.com/MiesSuomesta/STCP