Authors:
            
                    Akito Kiriyama
                    
                        
                                1
                            
                    
                    ; 
                
                    Yuji Nakagawa
                    
                        
                                1
                            
                    
                    ; 
                
                    Tadao Takaoka
                    
                        
                                2
                            
                    
                     and
                
                    Zhiqi Tu
                    
                        
                                2
                            
                    
                    
                
        
        
            Affiliations:
            
                    
                        
                                1
                            
                    
                    School of Informatics, Kansai University, Japan
                
                    ; 
                
                    
                        
                                2
                            
                    
                    University of Canterbury, New Zealand
                
        
        
        
        
        
             Keyword(s):
            Public-key cryptosystems, Non-linear knapsack problem, Access control.
        
        
            
                Related
                    Ontology
                    Subjects/Areas/Topics:
                
                        Enterprise Information Systems
                    ; 
                        Formal Methods
                    ; 
                        Information Systems Analysis and Specification
                    ; 
                        Methodologies and Technologies
                    ; 
                        Operational Research
                    ; 
                        Security
                    ; 
                        Simulation and Modeling
                    
            
        
        
            
                Abstract: 
                We propose in this paper a new public-key crypto-system, called the non-linear knapsack cryptosystem. The security of this system is based on the NP-completeness of the non-linear knapsack problem. We extend the system into secret sharing and access control. That is, an encrypted message can be decrypted only when all members of a group agree to do so with their secret sub-keys. The secret sharing here is equivalent to access control, which establishes multiple identities. That is, when the verifier challenges the prover with encrypted messages with public sub-keys, the prover can prove multiple identities using the secret sub-keys. Some experimental results are given, which demonstrate the efficiency of our system.