As far as I know, RSA/PKP patents are for _algorithms_, not respected outside the US, though patents for RSA/PKP _hardware_ would be respected worldwide. The patent on the RSA cryptosystem, whatever its content, only applies within the USA. There is no worldwide patent on the RSA cryptosystem. Activities not in the USA are not relevant to a USA patent. I'm not sure how algorithm patents can be applied to hardware -- you may or may not be able to sell this chip in the US _without_ violating patents. If the firmware on the chip does RSA, it's covered. If it merely does modular exponentiation, it's not. If the chip has an on-board programmable microcontroller and no RSA firmware, it's not covered by the patent, even if software can be loaded into the chip which does RSA. The device which loads the code in and which uses the loaded code, however, would be covered. You may even be able to apply for a European patent for the hardware, which would then be respected everywhere, except in the US where it may be superceded by the algorithm patents. Supercession like this does not happen. If there were a patent on the hardware and a patent on RSA both active in the same jurisdiction, one would have to obtain license from _both_ patent holders. Eric