Network security of Things along with the supply of IoT devices have been the latest conversation topics. With IoT generally consisting of Sensor device + Network + Cloud or IoT devices, Networking for data exchange of the devices is one of the main critical functions. As a result, the security function of exchanged data between devices is an essential element, not an option.



What is SSL/TLS?


SSL/TLS is the security password protocol at the transport layer. Because it runs on TCP-based, it can be widely applied and used in majority of communication methods using TCP/IP networks. For detailed information about SSL/TLS, please refer to the link below.



This document introduces the implementation and use of SSL/TLS on arm Cortex-M lightweight device.



Projects in WIZnetMuseum.com

1. pbTLS Security Dimension On Embedded Devices

WIZnetMuseum link: http://wiznetmuseum.com/portfolio-items/pbtls-security-dimension-on-embedded-devices/


PointBlank in Germany has developed pbTLS, a SSL/TLS library for lightweight embedded devices. PointBlank presented Benchmarks data for pbTLS based on arm Cortex-M4 168MHz / 20kByte RAM-based MCU from STMicroelectoronics and WIZnet W5500.


pbTLS can implement on platforms of various performance from arm Cortex-M0 to M7. It also can implement SSL/TLS-based communication with only about 50kByte Flash memory and minimum 500byte ~ maximum 16kByte RAM.


For more information, please refer to the links below.

pbTLS Specifications: https://www.pointblank.de/en/unique-technology.html

pbTSL Documentation: https://documentation.pointblank.de/



2. HTTPS client on STM32 Nucleo-F411RE

WIZnetMuseum link: http://wiznetmuseum.com/portfolio-items/https-client-on-stm32-nucleo-f411re/





The author ported mbedTLS from arm Mbed based on Nucleo-F411RE with arm Cortex-M4 from STMicroelectoronics and WIZnet W5100 Ethernet shield.

The author implemented and verified Simple ‘GET’ application with HTTPS(HTTP over SSL/TLS) in order to check the operation after SSL/TLS implementation. According to the author, about 90kByte of Flash memory and 50kByte of RAM are required to port MbedTLS.


3. Mutual Authentication and Key Agreement Scheme between Lightweight Devices in Internet of Things

(Mutual authentication and key agreement scheme between lightweight devices in Internet of Things)

WIZnetMuseum link: http://wiznetmuseum.com/portfolio-items/mutual-authentification-and-key-agreement-scheme-between-lightweight-devices-in-iot-research-paper/




SSL/TLS is a security technology based on TCP that is widely used to provide security service of IoT device. But, UDP-based DTLS (Datagram TLS) protocol has been proposed for lightweight devices in restrictive environments on resources.

The following paper suggests mutual authentication technology to ensure security between ultra-light devices that DTLS protocol is also difficult to accommodate. The proposed system is implemented and verified with Android device and Arduino UNO(32KB Flash / 2KB RAM) + W5100 Ethernet Shield.


Curator: Eric Jung from WIZnet
E-mail: eric@wiznet.io