CycloneSSH is an SSHv2 library dedicated to embedded applications. It can be used to operate network services such as remote shell and file transfer over an unsecured network. The authentication layer of SSH uses public-key cryptography to authenticate the remote machine. The transport layer of SSH provides confidentiality and integrity of data exchanged between the client and server. CycloneSSH supports several Renesas products including the RA MCUs.



  • SSH version 2.0 implementation
  • Client and server modes of operation
  • Password and public key user authentication methods
  • Secure shell client and server (for remote execution of commands)
  • SCP client and serve & SFTP client and server
  • Key exchange using Diffie-Hellman, ECDH, Curve25519, and Curve448 algorithms
  • RSA, DSA, ECDSA, Ed25519, and Ed448 host key algorithms
  • 3DES, AES, Camellia, SEED, and Chacha20Poly1305 encryption algorithms
  • Legacy support for RC4, IDEA, and Blowfish encryption algorithms
  • CBC, CTR, and GCM encryption modes
  • HMAC using SHA-1, SHA-256 or SHA512
  • Legacy support for MD5 and RIPEMD-160 algorithms
  • Supports Encrypt-then-MAC (EtM) construction
  • Elliptic Curve Cryptography (ECC) supported
  • Flexible memory footprint. Built-time configuration to embed only the necessary features
  • Portable architecture (no processor dependencies)
  • The library is distributed as a full ANSI C and highly maintainable source code




  • Industrial IoT Systems
  • Home and Building Automation
  • Security and Defense Systems
  • Smart Meters and Energy Storage


Type Title Date
Product Brief PDF 570 KB
Presentation PDF 511 KB
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