Does your Application or Device Need SSL/TLS?

The CyaSSL embedded SSL library is a lightweight, portable, C-language-based SSL/TLS library targeted at IoT, embedded, and RTOS environments primarily because of its size, speed, and feature set. It works seamlessly in desktop, enterprise, and cloud environments as well. CyaSSL supports industry standards up to the current TLS 1.2 and DTLS 1.2, is up to 20 times smaller than OpenSSL, offers a simple API, an OpenSSL compatibility layer, OCSP and CRL support, is backed by the robust wolfCrypt cryptography library, and much more.

CyaSSL relies on the soon-to-be FIPS 140-2 validated wolfCrypt library for all cryptographic functionality.  For more information, see our FIPS FAQ.

Providing secure communication for IoT, smart grid, connected home, automobiles, routers, applications, games, IP, mobile phones, the cloud, and more.

Copyright 2015 wolfSSL Inc.  All rights reserved.

Embedded SSL Library

for Applications, Devices, IoT, and the Cloud

CyaSSL 3.3.0

Release 3.3.0 includes countermeasures from the Prosecco team, minimum downgrade version, small stack and sniffer improvements, PicoTCP support and more.

Read More

wolfCrypt Crypto Engine

A lightweight, embeddable, and easy-to-configure crypto library with a strong focus on portability, modularity, security, and feature set .  Read More.

Do You Need Help?

If you are looking for assistance, have run into a problem, or discovered a bug, please post to our support forums, email us, or call us at:  +1 425 245 8247.


A joint white paper published by wolfSSL and Intel titled “Implementation and Performance of AES-NI in CyaSSL Embedded SSL”, details using Intel’s hardware-accelerated AES instructions (AES-NI) with the CyaSSL lightweight SSL library. 

Implementation and Performance of AES-NI in CyaSSL Embedded SSL

wolfSSL | Intel

Download White Paper


wolfSSL focuses on creating high quality, portable, embedded security software.  Current products include the CyaSSL embedded SSL library, wolfCrypt embedded crypto engine, yaSSL Embedded Web Server, and wolfSSL JNI wrapper. As strong believers in open source, all of wolfSSL’s products are dual licensed under both the GPLv2 as well as standard commercial licensing.

To learn more about wolfSSL and the CyaSSL embedded SSL library, we invite you to read our About Us page, or visit a respective product page.


Are you curious about where wolfSSL products are used? CyaSSL is actively being used in a wide range of markets and products including the smart grid, IoT, industrial automation, connected home, M2M, auto industry, games, applications, databases, sensors, VoIP, routers, appliances, cloud services, and more.

Over 500,000,000 applications and devices are secured with wolfSSL products.

To learn more about specific markets which are currently using wolfSSL products, please visit our Case Studies page.


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