Secure Shell (SSH) encrypts communications between hosts over an insecure network, and it's great for logging into and executing commands remotely. It's also useful for port forwarding (sometimes called SSH Tunneling) which allows you to securely tunnel arbitrary TCP connections and for secure file transfers using the SFTP protocol.
Unfortunately, most SSH toolkits are designed for networked computers, not devices. That means that they can be somewhat unwieldy in memory-constrained device environments... and the performance of typical commercial or open-source SSH offerings can be pretty disappointing, as well.
NanoSSH™ is the answer.
NanoSSH is Mocana's super-fast, super- small SSH client/server solution with support for X509.v3 Certificate based authentication and comes with RADIUS client, specifically designed to speed product development while providing best-in-class device security services for resource-constrained environments. It's royalty-free and surprisingly affordable: the NanoSSH total cost of ownership is almost always less than that of open source. NanoSSH provides a holistic approach for securing networked devices and services, and is ideally suited for resource-constrained devices as well as high-traffic enterprise and federal environments where performance is critical. NanoSSH is open-standards-based, extensible, extremely small footprint, platform-agnostic and features an optional government-certified FIPS 140-2 level-1-validated crypto core. It even supports NSA Suite B crypto algorithms so your product can securely link civilian and classified government networks with a common cryptographic scheme.