the public key minefield

[Peter Baumbach]

[my silly public key example deleted]

> No, because of the language in the patent which requires that it be
> infeasible to find the deciphering key from the enciphering key.  Here's
> the claim, from patent 4218582, that covers all of public key cryptography:
> 
> 1. In a method of communicating securely over an insecure communication
> channel of the type which communicates a message from a transmitter to
> a receiver, the improvement characterized by:
>   providing random numbers at the receiver;
>   generating from said random numbers a public enciphering key at the
>     receiver;
>   generating from said random numbers a secret deciphering key at the
>     receiver such that the secret deciphering key is directly related to
>     and computationally infeasible to generate from the public enciphering
>     key;
>   communicating the public enciphering key from the receiver to the
>     transmitter;
>   processing the message and the public enciphering key at the
>     transmitter and generating an enciphered message by an enciphering
>     transformation, such that the enciphering transformation is easy to
>     effect but computationally infeasible to invert without the secret
>     deciphering key;
>   transmitting the enciphered message from the transmitter to the
>     receiver; and
>   processing the enciphered message and the secret deciphering key at
>     the receiver to transform the enciphered message with the secret
>     deciphering key to generate the message.

Doesn't a patent have to have enough information for a person skilled
in the art to construct a prototype?  

I publish for the first time here my invention.  I will patent it within
a years time.  
                       Striped Vegetables

----
This isn't enough for anyone to do anything.  If I were more specific, I
might have something patentable, but then by claims wouldn't be as broad.
If you figured out how to make an anti-gravity device.  That device would
be patentable.  The concept of "anti-gravity" device is not patentable.
If I could duplicate the effect of your anti-gravity device without using
any of the same novel mechanisms.  My device would be separately patentable.

Peter Baumbach
baumbach at atmel.com