Method and system for secure communications

• US 6,253,326 B1
• Filed: 05/29/1998
• Issued: 06/26/2001
• Est. Priority Date: 05/29/1998
• Status: Expired due to Term

• Current Assignee: Access Company Limited
• Original Assignee: Palm, Inc. (TCL Technology Group Corp.)
• Inventors: Lincke, Scott D., Marianetti, Ronald II
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/086,888
• Time in Patent Office: 1,124 Days
• Field of Search: 380/255, 380/270, 380/277, 380/281, 380/283, 713/168, 713/171, 713/193, 713/200, 713/201
• US Class Current: 726/12
• CPC Class Codes: G06F 16/9577 Optimising the visualization of content, e.g. distillation of HTML documents
• CPC Class Codes: G06F 16/958 Organisation or management of web site content, e.g. publishing, maintaining pages or automatic linking
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/75 Indicating network or usage conditions on the user display
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/165 Combined use of TCP and UDP protocols; selection criteria therefor
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A communications system and methods for securely transmitting a message between a wireless client and a proxy server are provided. A method for transmitting a message from the wireless client to a proxy server is provided. The message includes at least one packet of data and is encrypted using a data encryption key. The data encryption key is encrypted using a proxy server public key prior to sending the encrypted data encryption key to the proxy server. A method for transmitting a message from the proxy server to the wireless client is also provided. The proxy server recovers the data encryption key using the proxy server private key corresponding to the proxy server public key. The proxy server encrypts the message using the data encryption key and transmits the encrypted message to the wireless client. A communications system for secure communications comprising a source of data, a proxy server and a wireless client is also provided. Each transaction in the communications system comprises at least one request message and at least one response message. For each transaction, the wireless client encrypts a data encryption key using a proxy server public key. Messages exchanged between the wireless client and the proxy server are encrypted using the transaction specific data encryption key.

Claims

1. A method for securely transmitting a message from a wireless client, the method comprising:

encrypting a local key using a public key to form an encrypted local key, the local key corresponding to a request to contact a proxy server;

encrypting the message using the local key to form an encrypted message; and

transmitting the encrypted message to the proxy server, the encrypted message comprising at least one packet of data.

2. The method of claim 1, wherein each packet of data is formatted according to a compact transfer protocol.

3. The method of claim 1, further comprising generating the local key by,

applying a secure hash to a first input to form a first multibit hash, the first input comprising a concatenation of an output from a random number generator and at least one other character string; and

applying a message digest function to the first multibit hash to form the local key.

4. The method of claim 1, wherein the specific transaction comprises a single request message and each packet of data is less than one kilobyte.

6. The method of claim 4, further comprising signaling the encrypted request message to the proxy server with information to validate the encrypted request message.

5. A method for securely transmitting a message from a wireless client, the method comprising:

encrypting a local key using a public key on a proxy server to form an encrypted local key, the local key corresponding to a specific transaction between the wireless client and the proxy server;

encrypting the message using the local key to form an encrypted message; and

transmitting the encrypted message to the proxy server, the encrypted message comprising at least one packet of data, and a request message corresponding to a hypertext document, the encrypted request message further comprising encrypted request parameters, an encrypted bit, an encryption scheme identifier, a proxy server public key identifier, a proxy server identifier, a wireless client generated indication of current date and time, an encrypted request message integrity check, and the encrypted local key, the encrypted request parameters created from request parameters using the local key, the request parameters including compressed representations of data corresponding to fields in the hypertext document, the compressed representations formatted according to a compact transfer protocol, the encrypted request message integrity check encrypted using the local key.

7. A method for securely transmitting a message from a proxy server to a wireless client comprising:

receiving a message to be transmitted to the wireless device;

receiving an encrypted local key corresponding to a specific transaction between the proxy server and the wireless client;

decrypting the encrypted local key using a public key on the proxy server;

encrypting the message using the local key to form an encrypted message; and

transmitting the encrypted message to the wireless client.

8. The method of claim 7 wherein, the message comprises compressed data in a compact markup language.

9. The method of claim 7 wherein, the specific transaction comprises a single response message, and each packet of data is less than one kilobyte.

10. The method of claim 7, wherein prior to transmitting the encrypted message to the wireless client, the method further comprises:

computing a response message integrity check;

encrypting the response message integrity check using the local key to form an encrypted response message integrity check, the encrypted response message further comprising the encrypted response message integrity check.

11. The method of claim 10, further comprising after the transmitting step:

the wireless client receiving the encrypted response message;

the wireless client recovering the response message integrity check from the encrypted response message integrity check using the data encryption key; and

the wireless client verifying the response message integrity check.

12. A method for securely transmitting a message from a proxy server to a wireless client comprising:

receiving an encrypted request message comprising encrypted request parameters, a wireless client generated indication of current data and time, and a proxy server identifier, the encrypted request parameters formed by encrypting request parameters using the local key;

receiving an encrypted wireless client generated request message integrity check, the encrypted request message integrity check formed by encrypting a wireless client generated request message integrity check using the local key, the wireless client generated request message integrity check formed from a concatenation of the request message parameters, the wireless client generated indication of current data and time, and the proxy server identifier;

receiving a local key that was encrypted on the wireless client using a public key stored on a proxy server, the local key corresponding to a specific transaction between the proxy server and the wireless client;

decrypting the local key using a proxy server public key;

encrypting the message using the local key to form an encrypted message; and

transmitting the encrypted message to the wireless client.

13. The method of claim 12, further comprising:

recovering the client generated request message integrity check;

recovering the request message parameters;

computing a computed request message integrity check using the request message parameters, the wireless client generated indication of current data and time, and the proxy server identifier;

comparing the computed request message integrity check with the client generated request message integrity check;

responsive to the computed request message integrity check not matching the client generated request message integrity check, the proxy server throwing away the encrypted request message.

14. A system for secure communications comprising:

a source of data comprising means for transmitting markup language messages to a proxy server;

a wireless client coupleable to the proxy server, the wireless client comprising means for exchanging encrypted messages with the proxy server, the encrypted messages comprising encrypted request messages and encrypted response messages, each encrypted message comprising at least one packet of data, each encrypted request message comprising encrypted request parameters and an encrypted local key, the encrypted request parameters created by encrypting request parameters using the local key, the request parameters corresponding to fields in a hypertext document, the encrypted local key created by encrypting a local key on the wireless client using a proxy server public key, the local key corresponding to a transaction, the transaction comprising at least one request message and at least one response message, the HTML messages corresponding to the encrypted request messages; and

wherein the proxy server includes;

means for exchanging encrypted messages with the wireless client, each encrypted message comprising at least one packet of data;

means for fetching markup languages messages from the source of data;

means for recovering the local key from the encrypted local key using the proxy server public key;

wherein each encrypted request message further comprises an encrypted bit, an encryption scheme identifier, a proxy server public key identifier, a proxy server identifier, a wireless client generated indication of current date and time, and an encrypted request message integrity check.

15. The system of claim 14, wherein the request parameters comprise compressed representations of data corresponding to fields in the hypertext document, the compressed representations formatted according to a compact transfer protocol.

16. The system of claim 14, wherein the transaction comprises an encrypted single request message and an encrypted single response message.

17. The system of claim 14, wherein each packets of data is less than one kilobyte.

18. The system of claim 14, wherein the wireless client further comprises means for generating the local key.

19. A system for secure communications comprising:

a source of data comprising means for transmitting markup language messages to a proxy server;

a wireless client coupleable to the proxy server, the wireless client comprising means for exchanging a first encrypted message with the proxy server, the encrypted messages comprising encrypted request messages and encrypted response messages, each encrypted message comprising at least one packet of data, each encrypted request message comprising encrypted request parameters and an encrypted local key, the encrypted request parameters created by encrypting request parameters using the local key, the request parameters corresponding to fields in a hypertext document, the encrypted local key created by encrypting a local key on the wireless client using a proxy server public key, the local key corresponding to a transaction, the transaction comprising at least one request message and at least one response message, the HTML messages corresponding to the encrypted request messages; and

wherein the proxy server includes;

means for exchanging encrypted messages with the wireless client, each encrypted message comprising at least one packet of data;

means for fetching markup languages messages from the source of data;

means for recovering the local key from the encrypted local key using the proxy server public key; and

wherein the encrypted response message comprises a response message integrity check and compressed data in a compact markup language, the compressed data corresponding to a hypertext markup language message fetched per the encrypted request message, the compressed data comprising an indication of a bit size of the encrypted response message, an indication of whether the response is complete, and encrypted response message parameters, the proxy server further comprises;

means for validating the encrypted request message;

means for computing the response message integrity check; and

means for encrypting response message parameters and the response message integrity check, the means for encrypting comprising using the local key.

20. The system of claim 19, wherein the wireless client further comprises:

means for decrypting the encrypted response message integrity check and the response message using the local key; and

means for validating the response message integrity check.

21. A method for transmitting communications from a wireless device, the method comprising:

generating a local key on the wireless device responsive to a request for signaling a communication from the wireless device, the communication comprising at least one packet of data;

encrypting the local key using a public key located on a proxy server;

encrypting the communication using the local key; and

transmitting the encrypted communication and the encrypted local key to the proxy server.

22. The method of claim 21, wherein the communication includes a hypertext markup language message.

23. The method of claim 21, further comprising:

generating a message integrity check, the message integrity check including one or more parameters to enable the proxy server to check that the communication originated from the wireless device.

24. The method of claim 23, further comprising encrypting the message integrity check;

and

transmitting the message integrity check as part of the communication to the proxy server.

25. The method of claim 21, further comprising:

receiving a request to transmit a hypertext document; and

wherein encrypting the communication includes encrypting the hypertext document.

26. A method for communicating with a wireless handheld computer, the method comprising:

receiving an encrypted local key generated on the wireless handheld computer;

decrypting the local key using a public key located on a server;

encrypting a message using the local key; and

signaling the message to the wireless handheld computer.

27. The method of claim 26, wherein receiving an encrypted local key includes receiving a communication from the wireless handheld computer, the communication comprising the local key.

28. The method of claim 26, further comprising receiving an encrypted communication comprising the local key, and decrypting the communication to identify the local key.

29. The method of claim 26, wherein signaling the message to the wireless handheld computer is responsive to receiving an encrypted message from the wireless handheld computer, the encrypted message including the encrypted local key.

30. The method of claim 26, further comprising receiving the message to be encrypted and signaled to the wireless handheld computer from a network.

31. A method for communicating with a wireless handheld computer, the method comprising:

receiving an encrypted communication from a wireless handheld computer;

accessing a public key;

recovering a local key from the encrypted communication using the public key; and

recovering a communication from the wireless handheld computer using the local key.

32. The method of claim 31, further comprising validating that the encrypted communication received from the wireless handheld computer.

33. The method of claim 32, wherein validating that the encrypted communication received from the wireless handheld computer includes identifying a time of day that the encrypted communication was signaled from the wireless handheld computer.

34. The method of claim 33, wherein validating the encrypted message received from the wireless handheld computer includes comparing the time of day that the encrypted communication was signaled from the wireless handheld computer with a time of day that the encrypted communication was received from the wireless handheld computer.

35. The method of claim 34, wherein receiving an encrypted communication from the wireless handheld computer includes receiving the time of day that the communication was signaled from the wireless handheld computer as part of the encrypted communication.

36. The method of claim 32, wherein validating that the encrypted communication received from the wireless handheld computer includes identifying at least one of a server identification for receiving the communication and a time of day.