RFC 4432 RSA Key Exchange for the Secure Shell (SSH) Transport Layer Protocol
This memo describes a key-exchange method for the Secure Shell (SSH)
protocol based on Rivest-Shamir-Adleman (RSA) public-key encryption.
It uses much less client CPU time than the Diffie-Hellman algorithm
specified as part of the core protocol, and hence is particularly
suitable for slow client systems.