Method and system for strongly encrypting .zip files

Abstract

The present invention provides a method of integrating existing strong encryption methods into the processing of a .ZIP file to provide a highly secure data container which provides flexibility in the use of symmetric and asymmetric encryption technology. The present invention adapts the well established .ZIP file format to support higher levels of security and multiple methods of data encryption and key management, thereby producing a highly secure and flexible digital container for electronically storing and transferring confidential data.

1 - 24 . (canceled)  
     
     
         25 . A method of placing data in a .Zip file format data container, said method including: 
 receiving a data file at an application;    compressing said data file using said application before encrypting said data file;    encrypting said data file to form encrypted data using said application, wherein said encrypting includes encrypting said data file using symmetric encryption having a key length of at least 128 bits; and    placing said encrypted data in a data container using said application, wherein said data container is constructed in accordance with a .Zip file format, wherein said data container includes an indication of the encryption method employed in encrypting said data file.    
     
     
         26 . The method of  claim 25  wherein said compressing employs a Lempel-Ziv (LZ)-type data compression algorithm.  
     
     
         27 . The method of  claim 25  wherein said compressing employs a Deflate-type data compression algorithm.  
     
     
         28 . The method of  claim 25  wherein said compressing employs a Burrows-Wheeler Transform (BWT)-type data compression algorithm.  
     
     
         29 . The method of  claim 25  wherein said data file has not been previously compressed.  
     
     
         30 . The method of  claim 25  wherein said key length is at least 192 bits.  
     
     
         31 . The method of  claim 25  wherein said key length is at least 256 bits.  
     
     
         32 . The method of  claim 25  further including: 
 generating symmetric key data during said encrypting of said data file.    
     
     
         33 . The method of  claim 32  further including: 
 placing said symmetric key data in said data container.    
     
     
         34 . A .Zip file format data container stored on a computer-readable medium, said data container including: 
 an encrypted data file,    wherein said encrypted data file has been encrypted by an application using symmetric encryption having a key length of at least 128 bits,    wherein said encrypted data file has been compressed by said application before encryption,    wherein said data container is constructed by said application in accordance with a .Zip file format,    wherein said data container includes an indication of the encryption method employed in encrypting said data file.    
     
     
         35 . The .Zip file format data container of  claim 34  wherein said encrypted data has been compressed before encryption using a Lempel-Ziv (LZ)-type data compression algorithm.  
     
     
         36 . The .Zip file format data container of  claim 34  wherein said encrypted data has been compressed before encryption using a Deflate-type data compression algorithm.  
     
     
         37 . The .Zip file format data container of  claim 34  wherein said encrypted data has been compressed before encryption using a Burrows-Wheeler Transform (BWT)-type data compression algorithm.  
     
     
         38 . The Zip file format data container of  claim 34  wherein said encrypted data has not been compressed before encryption.  
     
     
         39 . The .Zip file format data container of  claim 34  wherein said key length is at least 192 bits.  
     
     
         40 . The .Zip file format data container of  claim 34  wherein said key length is at least 256 bits.  
     
     
         41 . The Zip file format data container of  claim 34  further including: 
 symmetric key data,    wherein said symmetric key data is generated during said encrypting of said encrypted data.    
     
     
         42 . A method of placing data in a data container, said method including: 
 receiving a data file at an application;    compressing said data file using said application before encrypting said data file;    encrypting said data file to form encrypted data using said application, wherein said encrypting includes encrypting said data file using symmetric encryption having a key length of at least 128 bits; and    placing said encrypted data in a data container using said application, wherein said data container is designed for containing compressed files,    wherein said data container includes an indication of the encryption method employed in encrypting said data file.    
     
     
         43 . The method of  claim 42  wherein said compressing employs a Lempel-Ziv (LZ)-type data compression algorithm.  
     
     
         44 . The method of  claim 42  wherein said compressing employs a Deflate-type data compression algorithm.  
     
     
         45 . The method of  claim 42  wherein said compressing employs a Burrows-Wheeler Transform (BWT)-type data compression algorithm.  
     
     
         46 . The method of  claim 42  wherein said data file has not been previously compressed.  
     
     
         47 . The method of claim  424  wherein said key length is at least 192 bits.  
     
     
         48 . The method of  claim 42  wherein said key length is at least 256 bits.  
     
     
         49 . The method of  claim 42  further including: 
 generating symmetric key data during said encrypting of said data file.    
     
     
         50 . The method of  claim 49  further including: 
 placing said symmetric key data in said data container.    
     
     
         51 . The method of  claim 42  wherein said data container is constructed in accordance with a .Zip file format.  
     
     
         52 . A data container stored on a computer-readable medium, said data container including: 
 an encrypted data file,    wherein said encrypted data file has been encrypted by an application using symmetric encryption having a key length of at least 128 bits,    wherein said encrypted data has been compressed by said application before encryption,    wherein said data container is designed by said application for containing compressed files,    wherein said data container includes an indication of the encryption method employed in encrypting said data file.    
     
     
         53 . The data container of  claim 52  wherein said encrypted data has been compressed before encryption using a Lempel-Ziv (LZ)-type data compression algorithm.  
     
     
         54 . The data container of  claim 52  wherein said encrypted data has been compressed before encryption using a Deflate-type data compression algorithm.  
     
     
         55 . The data container of  claim 52  wherein said encrypted data has been compressed before encryption using a Burrows-Wheeler Transform (BWT)-type data compression algorithm.  
     
     
         56 . The data container of  claim 52  wherein said encrypted data has not been compressed before encryption.  
     
     
         57 . The data container of  claim 52  wherein said key length is at least 192 bits.  
     
     
         58 . The data container of  claim 52  wherein said key length is at least 256 bits.  
     
     
         59 . The data container of  claim 52  further including: 
 symmetric key data,    wherein said symmetric key data is generated during said encrypting of said encrypted data.    
     
     
         60 . The data container of  claim 52  wherein said data container is constructed in accordance with a .Zip file format.