 Since a detailed description of the algorithm had been published in the Mathematical Games column in the August 1977 issue of Scientific American, prior to the December 1977 filing date of the patent application, regulations in much of the rest of the world precluded patents elsewhere and only the US patent was granted.Had Cocks's work been publicly known, a patent in the United States would not have been legal either.From the DWPI's abstract of the patent,
The RSA algorithm involves four steps