Tectia Server for IBM z/OS can use a key created with OpenSSH as the server host key. The key must be configured with the HostKeyFile option in sshd2_config or have the default file names, hostkey and hostkey.pub.

Both RSA and DSA keys of sizes from 512 to 4096 bits or more are supported, as well as ECC keys of sizes 256, 384, and 521 bits.