When do patents expire on Rabin's public key scheme? RSA claims that the Diffie Helman patent, which expires on the 29th of April, 1997, covers all public key cryptography. ElGamal and Rabin are unpatented. Schmeier says that ElGamal will be free of patent restrictions after that, but he says nothing about Rabin. Rabin's encryption and signatures take up the same amout of space as RSA signatures, and encryption, but ElGamal takes up twice the space, thus Rabin seems preferable to ElGamal. --------------------------------------------------------------------- | We have the right to defend ourselves | http://www.jim.com/jamesd/ and our property, because of the kind | of animals that we are. True law | James A. Donald derives from this right, not from the | arbitrary power of the state. | jamesd@echeque.com