Secure method of synchronizing cache contents of a mobile browser with a server

• US 20070180125A1
• Filed: 07/21/2006
• Published: 08/02/2007
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Knowles, Michael, Kalougina, Tatiana, Tapuska, David
• Granted Patent: US 8,195,763 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC

Abstract

A method of securely synchronizing cache contents of a mobile browser with a server includes initiating a session between the browser and server, including transmission of browser state information regarding the cache contents and an authentication key to the server; maintaining a record of data sent from the server to the browser for storage in the cache; maintaining a record of the state information regarding the cache contents transmitted from the browser to the server; and transmitting data requests from the browser to the server, in response to which the server uses the key as a seed generation function and accesses each the record of data and returns only data that does not already form part of the cache contents, and wherein the data includes a result of a hash of data generated by the generation function for authentication by the browser before updating the cache contents with the data.

Claims

1. A secure method of synchronizing cache contents of a mobile browser with a server, comprising:

initiating a session between said browser and server, said session conforming to an out-of-band protocol, including transmission of browser state information regarding said cache contents and an authentication key to said server, said browser state information being in the form of a hash value;

maintaining a record of data sent from the server to the browser for storage in said cache;

maintaining a record of said state information regarding said cache contents transmitted from the browser to said server; and

transmitting data requests from said browser to said server, in response to which said server uses said authentication key to generate a message authentication code that includes a cryptographic hash of data, and accesses each said record of data and returns only data that does not already form part of said cache contents, and wherein said returned data includes a result of a hash of data generated using said authentication key for authentication by said browser before updating the cache contents with said data.

2. The method of claim 1, wherein said protocol includes a transitional state message with payload including said hash of said cache contents and a connection identifier, for notifying the server of current state information for a current session between said browser and the server.

3. The method of claim 1, wherein said protocol includes a transitional state message for notifying the server of changes in state during said current session between said browser and the server.

4. The method of claim 1, wherein said protocol includes a transitional state message for notifying the server that the browser has ceased sending messages using said connection identifier.

5. The method of claim 4, wherein the server de-allocates stored memory for the session in response to being notified that the browser has ceased sending messages using said connection identifier.

6. The method of claim 5, wherein data transmission according to said protocol comprises, in sequence:

a header representing said transitional state message;

, a protocol identifier and a Content-Length header;

a sequence of control characters; and

an XML-encoded document containing said hash value, a connection identifier and state information.

7. A communication system for secure synchronizing of mobile browser cache contents with a server, comprising:

a transmitter within said mobile device browser for initiating a session between said browser and server, said session conforming to an out-of-band protocol, and transmitting browser state information regarding said cache contents and an authentication key to said server, said browser state information being in the form of a hash value;

cache memory within said mobile device for maintaining a record of data sent from the server to the browser;

memory within said proxy server for maintaining a record of said state information regarding said cache contents transmitted from the browser to said server; and

a processor within said server for receiving data requests from said browser and in response using said authentication key to generate a message authentication code that includes a cryptographic hash of data, accessing each said record of data and returning to said mobile device browser only data that does not already form part of said cache contents, and wherein said returned data includes a result of a hash of data generated by said authentication key for authentication by said browser before updating the cache contents with said data.