Strange, I didn't expect Rambus to be involved in cryptography, nor that they would give away the spec and implementation. I guess it was designed to be a smaller die-area solution for some of their silicon IP products, and opening it up just makes it more convenient for their customers to use. (And, hopefully, nobody is stupid enough to use some vendor's secret proprietary crypto in their chips).

I'd be interested to read a history of Rambus. They're a strange and somewhat controversial company. I lived through the controversy but I'm not certain I remember it correctly. From what I remember they patented some things related to DDR SDRAM, I'm not sure how much credit they deserve for developing those things or if they were just first to file. For part of the Pentium 4's lifecycle they convinced Intel to use Rambus' proprietary DRAM (RDRAM) which supposedly had some benefits but I just remember being overpriced. They shook down DDR manufacturers for patent licensing fees. Apparently the EU opened an antitrust investigation into them for getting their patents into the standard and then not licensing them freely enough. I'm not sure it's fair to call them a patent troll but I guess they're something similar to Fraunhofer or Synopsis.