This sounds like ephemeral diffie hellman. Is that still protected by patents? I wouldn't think so seeing we've had robust implementations in openssl for a long time now.
> The Secure Remote Password protocol (SRP) is an augmented password-authenticated key agreement (PAKE) protocol, specifically designed to work around existing patents.[1]
They're related in that the derivation of session secrets is done through a simple modular exponentiation. Pretty much nothing else, from the generation of keypairs to the selection of groups to work in to the way parameters have to be checked, are the same.