METHOD AND SYSTEM FOR STRONGLY ENCRYPTING .ZIP FILES

• US 20080046761A1
• Filed: 07/06/2007
• Published: 02/21/2008
• Est. Priority Date: 07/16/2003
• Status: Abandoned Application

• Current Assignee: PKWARE, Inc. (PKW Holdings, Inc.)
• Original Assignee: PKWARE, Inc. (PKW Holdings, Inc.)
• Inventors: Peterson, James
• Application Number:
  US11/774,317
• Publication Number:
  US 20080046761A1
• Time in Patent Office: Days
• US Class Current: 713/193
• CPC Class Codes: G06F 16/1744 using compression, e.g. sparse files
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06F 2221/2153 Using hardware token as a secondary aspect
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 9/0819 Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) network architectures or network communication protocols for key distribution in a packet data network H04L63/062
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068

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.

Claims

1-24. -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.

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.

47. The method of claim 424 wherein said key length is at least 192 bits.

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.