Method and apparatus for encrypting data in a wireless communication system

Abstract

A method of transforming a set of signals representing a message comprising the steps of first encoding one of the set of signals according to a first keyed transformation, a second encoding of the one of the set of signals in accordance with at least one additional keyed transformation, a third encoding of the one of the set of signals according to a self inverting transformation in which at least one of the set of signals is altered, a fourth encoding of the one of the set of signals according to at least one additional inverse keyed transformation wherein each of the at least one additional inverse keyed transformation is a corresponding inverse of at least one additional keyed transformation, and fifth encoding the one of the set of signals according to first inverse keyed transformation wherein the first inverse keyed transformation is the inverse of the first keyed transformation.

We claim:  
     
         1 . A method for encrypting data, comprising: 
 transforming said data using portions of an authentication key in a first order to provide a transformed value; and    performing an additional transformation on said transformed value using at least one of said portions of said authentication key.    
     
     
         2 . The method of  claim 1  wherein said authentication key comprises 64 bits and said portions of said authentication key comprises eight eight-bit non overlapping portions of said authentication key.  
     
     
         3 . A communications device for transmitting data, comprising: 
 memory for storing an authentication key;    processor for retrieving portions of said authentication key from said memory and transforming said data using said portions of said authentication key in a first order to provide a transformed value and performing an additional transformation on said transformed value using at least one of said portions of said authentication key.    
     
     
         4 . The communications device of  claim 3  further comprising a transmitter for transmitting said encrypted version of said data.  
     
     
         5 . The communications device of  claim 3  wherein said communications device is a wireless base station.  
     
     
         6 . The communications device of  claim 3  wherein said communications device is a wireless remote station.  
     
     
         7 . A communications device for receiving encrypted data, comprising: 
 memory for storing an authentication key; and    processor for retrieving portions of said authentication key from said memory and for transforming said data using said portions of said authentication key in a first order to provide a transformed value and performing an additional transformation on said transformed value using at least one of said portions of said authentication key.    
     
     
         8 . The communications device of  claim 7  further comprising a receiver for receiving said encrypted version of said data.  
     
     
         9 . The communications device of  claim 7  wherein said communications device is a wireless base station.  
     
     
         10 . The communications device of  claim 7  wherein said communications device is a wireless remote station.  
     
     
         11 . A communications system, comprising: 
 first communications device for transforming data for transmission using portions of an authentication key in a first order to provide a transformed value and performing an additional transformation on said transformed value using at least one of said portions of said authentication key to provide encrypted data and for transmitting said encrypted data; and    second communications device storing a key wherein the value of said key is equal to the value of said authentication key in said first communications device, said second communications device for receiving said encrypted data transforming said encrypted data using portions of said key in a first order to provide a transformed value and performing an additional transformation on said transformed value using at least one of said portions of said key to provide a decoded version of said data.    
     
     
         12 . The communications system of  claim 11  wherein said first communications device comprises: 
 memory for storing said authentication key; and  
 processor for retrieving said encryption value from said table of encryption values and transforming data in accordance with said portions of said authentication key.  
 
     
     
         13 . The communications system of  claim 10  wherein said first communications device further comprises a transmitter for transmitting said encrypted version of said data.  
     
     
         14 . The communications system of  claim 11  wherein said second communications device, comprises: 
 memory for storing said key; and  
 processor for retrieving an value from said table of values and transforming said encrypted data in accordance with said portions of said key.