Method and apparatus for secure data storage and retrieval

• US 6,931,549 B1
• Filed: 05/25/2000
• Issued: 08/16/2005
• Est. Priority Date: 05/25/2000
• Status: Expired due to Term

• Current Assignee: Stamps.com, Inc.
• Original Assignee: Stamps.com, Inc.
• Inventors: Ananda, Mohan
• Primary Examiner(s): Morse, Gregory
• Assistant Examiner(s): Tran, Tongoc
• Application Number:
  US09/579,079
• Time in Patent Office: 1,909 Days
• Field of Search: 713200-201, 713/150, 713/155, 713/161, 713/169, 713/170, 713/171, 713/176, 713/175, 713/178
• US Class Current: 726/26
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• 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 2221/2101 Auditing as a secondary aspect
• CPC Class Codes: H04L 9/0838 Key agreement, i.e. key establishment technique in which a shared key is derived by parties as a function of information contributed by, or associated with, each of these network architectures or network communication protocols for key exchange in a packet data network H04L63/061
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3297 involving time stamps, e.g. generation of time stamps

Abstract

A method and system for secure real time storage and retrieval of data by a first computer with the aid of a second computer via a secure communication link between the first and second computers. The method and system enable a user at the remote first computer to secure a data file for storage by connecting to the second computer and by exchanging certain parameters between the two computers. The method and system also enable the user at the first computer to retrieve the stored secure data file by connecting to the second computer and by exchanging certain parameters between the two computers.

Claims

1. In a computer system, a method for securing access to data, comprising:

generating a first message at a first computer system, said first message comprising information corresponding to data, and transmitting said first message to a second computer system;

receiving said first message at said second computer system, and generating a key pair comprising an encode key and a decode key for encoding and decoding of said data;

generating a second message comprising said encode key, and transmitting said second message to said first computer system;

receiving said second message at said first computer system, wherein said encode key in said second message is used to encode said data;

providing access to said encoded data by;

generating a third message at said first computer system, said third message comprising information identifying said encoded data, said user information, and a digital signature;

transmitting said third message to said second computer system;

receiving said third message at said second computer system;

using said information in said third message to retrieve a record corresponding to said encoded data, said record comprising said decode key for decoding said encoded data;

verifying a stored digital signature in said corresponding record with said digital signature in said third message;

upon successful verification, generating a data retrieval time stamp and storing said data retrieval time stamp;

generating a fourth message comprising said decode key, and transmitting said fourth message to said first computer system; and

receiving said fourth message at said first computer system, wherein said decode key in said fourth message is utilized to decode said encoded data.

2. The method of claim 1 further comprising:

storing said key pair and said information in said first message in a database record.

3. The method of claim 1 wherein said first computer system comprises at least one client computer system and said second computer system comprises at least one server computer system.

4. The method of claim 1 wherein said generating said first message further comprises:

generating a one way hash function associated with said data; and

placing said one way hash function, information identifying said data, and user information associated with a user of said data at said first computer system in said first message.

5. The method of claim 4 further comprising:

after receiving said first message at said second computer;

generating a time stamp and a first digital signature representing said digital time stamp and said one way hash function in said first message; and

storing said user information, said information identifying said data, said one way hash function, said one way time stamp and said first digital signature.

6. The method of claim 5 wherein said second message further comprises:

said time stamp, said information identifying said data, and said first digital signature.

7. The method of claim 1 further comprising:

upon unsuccessful verification, generating an attempted data retrieval time stamp and storing said attempted data retrieval time stamp.

8. In a computer system, a method for providing secure real time storage and retrieval of file data comprising:

obtaining a secure save command from a user operating a screen element of a first computer system;

executing said secure save command to securely save file data at said first computer system, said executing comprising;

generating a first message at said first computer system, said first message comprising information corresponding to said file data, and transmitting said first message to a second computer system;

receiving said first message at said second computer system and generating a key pair comprising an encode key and a decode key for encoding and decoding of said file data;

generating a second message comprising said encode key and transmitting said second message to said first computer system; and

receiving said second message at said first computer system, wherein said encode key in said second message is used to encode said file data;

wherein said secure save command is performed by a component of a graphical user interface presenting command buttons on a user tool bar on said first computer system.

9. The method of claim 8 wherein registration functions are performed on said second computer system while said first computer system and said second computer systems maintain a secure link to each other.

10. The method of claim 9 wherein authentication functions are performed on said second computer system while said first computer system and said second computer systems maintain a secure link to each other.

11. The method of claim 8 wherein said secure link utilizes cryptographic protocols.

12. A method of providing secure real time storage and retrieval of data comprising:

maintaining a secure link between a first computer system and a second computer system while performing registration functions on said second computer;

maintaining said secure link between said first computer system and said second computer system while performing authentication functions on said second computer system, wherein said authentication comprises obtaining an identity for said first computer system;

obtaining a secure save command from a user, wherein said secure save command is embedded into a graphical user interface of said first computer system and said user of said secure save command of said graphical user interface initiates a process comprising the steps of;

generating a first message at said first computer system, said first message comprising information corresponding to said file data and said identity, and transmitting said first message to said second computer system;

receiving said first message at said second computer system and generating an encode key for encoding said file data and generating a decode key for decoding said file data;

generating a second message comprising said encode key, and transmitting said second message to said first computer system;

receiving said second message at said first computer system, wherein said encode key in said second message is utilized to encode said file data;

accessing encoded file data by generating a third message at said first computer system, said third message comprising information corresponding to said encoded file data, and transmitting said third message to said second computer system;

receiving said third message at said second computer system, and using said information in said third message to retrieve a record corresponding to said encoded data, said record comprising said decode key for decoding said encoded data;

generating a fourth message comprising said decode key and said information corresponding to said encoded file data, and transmitting said fourth message to said first computer system;

receiving said fourth message at said first computer system, and using said decode key in said fourth message to decode said encoded file data.

13. The method of claim 12, wherein said step of generating said first message further comprises:

generating a one way hash function of said file data; and

placing said hash function, information identifying said file data, and user information for a user of said file data at said first computer system in said first message.

14. The method of claim 13, further comprising:

obtaining said first message at said second computer;

generating a time stamp, and a digital signature representing said digital time stamp, and said hash function in said first message; and

storing said user information, said information identifying said data, said hash function, said time stamp and said digital signature in a database record.

15. The method of claim 14 wherein said second message further comprises:

said time stamp, said information identifying said file data, and said digital signature in said second message.

16. The method of claim 12 wherein said encoded file data may be stored at a third computer system.

17. A method for providing secure storage of data, comprising:

transmitting a secure save request from a client to a server, said secure save request comprising a file name associated with a data file, an identification value associated with said client, and a one-way hash function of said data file;

generating a storage timestamp at said server;

generating a digital signature at said server based on said storage timestamp and said one-way hash function;

generating, at said server, a first encryption key for encoding and a second encryption key for decoding;

storing said file name, said identification value, said storage timestamp, said digital signature and said second encryption key in a database record;

transmitting a secure save response from said server to said client, said secure save response comprising said file name, said digital signature, and said first encryption key;

using said first encryption key and said data file to obtain encrypted data at said client; and

storing said encrypted data and said digital signature in association with said file name.

18. The method of claim 17, further comprising:

transmitting a secure retrieve request from said client to said server, said secure retrieve request comprising said file name, said identification value and said digital signature;

said server comparing said file name, said identification value and said digital signature from said secure retrieval request with said file name, said identification value and said digital signature from said database record;

when said comparing is a match,

generating a retrieval success timestamp and storing said retrieval success timestamp in said database record;

transmitting a secure retrieval response from said server to said client, said secure retrieval response comprising said file name and said second encryption key; and

said client using said second encryption key to decode said encrypted data.

19. The method of claim 18, further comprising, when said comparing is not a match:

generating a retrieval attempt timestamp; and

storing said retrieval attempt timestamp in said database record.

20. The method of claim 18, further comprising:

said client auditing said database record to obtain an access history comprising said storage timestamp and said retrieval success timestamp.

21. The method of claim 17, further comprising:

transmitting a second secure save request from said client to said server, said second secure save request comprising said file name;

said server generating a third encryption key for encoding and a fourth encryption key for decoding, wherein said third encryption key and said fourth encryption key differ from said first encryption ey and said second encryption key, respectively.