Ex parte SPRUNK - Page 2




          Appeal No. 2000-1330                                                        
          Application No. 08/972,835                                                  


          high level of security against attackers.  At the same time,                
          with knowledge of a secret distribution key, a government                   
          agency is presented with a lower work factor.                               
               Independent claim 1 is reproduced as follows:                          
               1.  A method for providing a cryptographic key for                     
          cryptographically processing information, said method                       
          comprising the steps of:                                                    
               (a) generating a first key according to a key generator                
          scheme;                                                                     
               (b) reducing a key space of said first key in accordance               
          with a key space reduction function; and                                    
               (c) distributing said reduced key space over a larger key              
          space in accordance with a one-way key space distribution                   
          function to provide said cryptographic key; wherein:                        
               said cryptographic key has an associated first work                    
          factor S for a person without knowledge of said key space                   
          distribution function; and                                                  
               said cryptographic key has an associated second work                   
          factor W < S for a person with knowledge of said key space                  
          distribution function.                                                      
               The Examiner relies on the following references:                       
          Elander et al. (Elander)      5,323,464                June 21,             
                                                  1994                                
          Applied Cryptography, Bruce Schneier, CIP of 1993 and                       
          copyright of 1994.                                                          
               Claims 1 through 6, 8 through 20 and 23 through 31 stand               
          rejected under 35 U.S.C. § 103 as unpatentable over Elander.                
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