Methods and systems for encrypting, transmitting, and storing electronic information and files

• US 7,725,716 B2
• Filed: 06/16/2005
• Issued: 05/25/2010
• Est. Priority Date: 06/28/2004
• Status: Active Grant

• Current Assignee: Japan Communications Inc.
• Original Assignee: Japan Communications Inc.
• Inventors: Tidwell, Justin Owen, Zeitz, Karlton Mark
• Primary Examiner(s): GERGISO, TECHANE
• Application Number:
  US11/154,840
• Publication Number:
  US 20050289655A1
• Time in Patent Office: 1,804 Days
• Field of Search: 713/186, 726/5, 726/27
• US Class Current: 713/168
• 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: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

Methods and systems for securely requesting, retrieving, sending, and storing files. One aspect involves receiving a request for a file from a client device that identifies a user and the client device, encrypting the file using a session key based at least in part on the user and the client device, and transmitting the encrypted file to the client device. Other aspects of the invention include storing the encrypted file on the client device in encrypted form such that the file may only be decrypted or accessed by the particular user on that particular client device.

Claims

1. A method comprising:

receiving a request for a file and receiving a user and device key, wherein the request identifies a user and a client device that sent the request and the user and device key;

generating a session key that is unique for the user, device, and session;

creating a session-key-encrypted file by encrypting the file using the session key;

creating an encrypted message by encrypting the session-key-encrypted file and the session key together using the user and device key; and

transmitting the encrypted message to the client device, wherein the client device decrypts the encrypted message, stores the session-key-encrypted file, stores the session key, and restricts access to the session key such that the session key is only provided to the user on the client device, wherein, after the session and communication to the client device has ended, the session-key-encrypted file and the session key are only available for use by the user on the client device.

2. The method of claim 1, wherein the request for the file and the user and device key that are received are received encrypted.

3. The method of claim 1 further comprising retrieving the file from a database prior to encrypting the file.

4. The method of claim 1 further comprising determining whether the user has access to the file prior to encrypting the file.

5. A method comprising:

sending a request for a file and sending a user and device key from a client device to a server wherein a user is using the client device;

receiving the file from the server, wherein the file is encrypted in an encrypted message, wherein the encrypted message was encrypted using the user and device key;

decrypting the encrypted message to retrieve a session-key-encrypted file and a session key unique for the user, device, and session, the session-key-encrypted file comprising the requested file that was encrypted by the server using the session key; and

storing the session-key-encrypted file and the session key on the client device, and restricting access to the session key such that the session key is only provided to the user on the client device, wherein, after the session and communication to the client device has ended, the session-key-encrypted file and the session key are only available for use by the user on the client device.

6. The method of claim 5 wherein the request is encrypted based on a public key associated with the server.

7. A computer readable storage medium having program code stored thereon and executable by a device, comprising:

program code for receiving a request for a file and receiving a user and device key, wherein the request identifies a user and a client device that sent the request and the user and device key;

program code for generating a session key that is unique for the user, device, and session;

program code for creating a session-key-encrypted file by encrypting the file using the session key;

program code for creating an encrypted message by encrypting the session-key-encrypted file and the session key together using the user and device key; and

program code for transmitting the encrypted message to the client device, wherein the client device decrypts the encrypted message and stores the session-key-encrypted file, stores the session key, and restricts access to the session key such that the session key is only provided to the user on the client device, wherein, after the session and communication to the client device has ended, the session-key-encrypted file and the session key are only available for use by the user on the client device.

8. The computer readable storage medium of claim 7 having program code for decrypting the request for the file.

9. The computer readable storage medium of claim 7 having program code for retrieving the file from a database prior to encrypting the file.

10. The computer readable storage medium of claim 7 having program code for determining whether the user has access to the file prior to encrypting the file.

11. A computer readable storage medium having program code stored thereon and executable by a device, comprising:

program code for sending a request for a file and sending a user and device key from a client device to a server, wherein a user is using the client device;

program code for receiving the file from the server, wherein the file is encrypted in an encrypted message, wherein the encrypted message was encrypted using the user and device key;

program code for decrypting the encrypted message to retrieve a session-key-encrypted file and a session key unique for the user, device, and session, the session-key-encrypted file comprising the requested file that was encrypted by the server using the session key; and

program code for storing the session-key-encrypted file and the session key on the client device, and restricting access to the session key such that the session key is only provided to the user on the client device, wherein, after the session and communication to the client device has ended, the session-key-encrypted file and the session key are only available for use by the user on the client device.