RPN patented?

I found this
Encryption using a user-known and personally valuable key to deter key sharing
i havent had the time to read it all but it looks like we might have to get a premission to use the RPN metod.
Somebodey correct me if im wrong.
Encryption using a user-known and personally valuable key to deter key sharing
i havent had the time to read it all but it looks like we might have to get a premission to use the RPN metod.
Somebodey correct me if im wrong.