ENCRYPTED EMAIL BASED UPON TRUSTED OVERLAYS

• US 20100241847A1
• Filed: 03/17/2009
• Published: 09/23/2010
• Est. Priority Date: 03/17/2009
• Status: Active Grant

• Current Assignee: Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Original Assignee: Brigham Young University (The Church of Jesus Christ of Latter-Day Saints)
• Inventors: Seamons, Kent Eldon, van der Horst, Timothy W.
• Granted Patent: US 8,521,821 B2
• Time in Patent Office: Days
• US Class Current: 713/152
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/222 using geographical location information, e.g. messages transmitted or received in proximity of a certain spot or area
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 9/083 involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP]
• CPC Class Codes: H04L 9/3273 for mutual authentication network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869

Abstract

Sending and receiving encrypted emails. At a web browser, user input is received requesting a compose email page user interface for a web-based email system. The compose email page user interface is requested from a server for the web-based mail system. Web page code is received from the server for the compose email page user interface. The web page code for the compose email page user interface is parsed to determine screen locations of one or more user input interface elements. The compose email page user interface is rendered in the browser. One or more browser-based interface elements implemented integral to the browser are overlaid onto the compose email page user interface. User input is received in the browser user interface elements. The user input received is encrypted. The encrypted user input is transferred into one or more elements of the compose email page user interface.

Claims

1. At a web browser in a computing system, a method of sending a secure email, the method comprising:

receiving user input requesting a compose email page user interface for a web-based email system;

requesting the compose email page user interface from a server for the web-based mail system;

receiving web page code from the server for the compose email page user interface;

parsing the web page code for the compose email page user interface to determine screen locations of one or more user input interface elements including at least an email text box user input interface element;

rendering the compose email page user interface in the browser;

overlaying one or more browser-based interface elements implemented integral to the browser and separate from the web page code from the server onto the compose email page user interface, wherein one or more of the browser-based interface elements are displayed at one or more of the determined screen locations, including overlaying a browser-based text box user input interface element over the email text box user input interface element;

receiving user input in the browser-based text box user interface element;

encrypting the user input received in the browser-based text box user interface element;

transferring the encrypted user input into one or more elements of the compose email page user interface.

2. The method of claim 1 wherein transferring the encrypted user input into one or more elements of the compose email page user interface comprises transferring the encrypted user input into the email text box user input interface element overlaid by the browser-based text box user input interface element.

3. The method of claim 1 wherein transferring the encrypted user input into one or more elements of the compose email page user interface comprises transferring the encrypted user input into an email attachment user input interface element of the compose email page user interface.

4. The method of claim 1 further comprising modifying input into at least one of a subject line user interface element of the compose email page user interface, a to field user interface element of the compose email page user interface, a from field user interface element of the compose email page user interface;

a cc field user interface element of the compose email page user interface or the email text box user input interface element of the compose email page user interface to indicate that a secure email is being sent.

5. The method of claim 1, wherein encrypting the user input received in the browser-based text box user interface element comprises encrypting the user input using a key derived from a master secret from a key server, the key further being derived from an identifier identifying a sender of the email message and from an identifier identifying the receiver of the email message.

6. The method of claim 1, wherein encrypting the user input received in the browser-based text box user interface element comprises:

sending a request to a key server for a sender key, wherein the request includes an identification of an entity sending the secure email;

receiving a sender key, the sender key being derived from a master secret key and the identification of the entity sending the secure email;

generating a sender-recipient key using the sender key and an identification of a recipient of the secure email; and

using the sender-recipient key, encrypting the user input received in the browser-based text box user interface.

7. The method of claim 6, further comprising:

using the sender-recipient key to generate a plurality of purpose specific keys, including an encryption key, a method authentication code key, and a key identifier key;

wherein using the sender-recipient key, encrypting the user input received in the browser-based text box user interface element comprises using the encryption key to encrypt the user input received in the browser-based text box user interface element;

using the method authentication code key to provide integrity to both encrypted text and plaintext in the email; and

using the key identifier key to create a keyed fingerprint of a recipient'"'"'s identifier.

8. The method of claim 1, wherein the browser-based interface is implemented integral to the browser through the use of a browser plug-in.

9. The method of claim 1, wherein transferring the encrypted user input into one or more elements of the compose email page user interface occurs periodically as user input is received in the browser-based text box user interface element to allow auto saving of an encrypted draft at a web-based mail system server.

10. The method of claim 1, further comprising periodically, locally caching a plain text copy of the user input received in the browser-based text box user interface element.

11. The method of claim 1, wherein overlaying one or more browser-based interface elements onto the compose email page user interface, wherein the overlay is displayed at one or more of the determined screen locations, comprises overlaying one or more of a subject line user interface element of the compose email page user interface or an attachments interface element of the compose email page user interface.

12. The method of claim 1, wherein overlaying one or more browser-based interface elements onto the compose email page user interface, wherein the overlay is displayed at one or more of the determined screen locations comprises, overlaying one or more of a to field user interface of the compose email page user interface, a cc field user interface of the compose email page user interface, or a bcc field user interface of the compose email page user interface when the secure email will be sent using a relay server.

13. The method of claim 1, wherein overlaying a browser-based interface is performed in response to user input indicating a desire to send a secure email.

14. The method of claim 1, wherein overlaying a browser-based interface is performed as a default behavior, and wherein user input may be received at the browser indicating that the user does not desire to send a secure email.

15. At a web browser in a computing system, a method of receiving a secure email, the method comprising:

receiving user input requesting a read email page user interface for a web-based email system;

requesting the read email page user interface from a server for the web-based email system;

receiving web page code from the server for the read email page user interface;

parsing the web page code for the read email page user interface to determine screen locations of one or more user interface elements including at least an email text box user output interface element;

rendering the read email page user interface in the browser;

overlaying one or more browser-based interface elements implemented integral to the browser and separate from the web page code onto the read email page user interface, wherein one or more of the browser-based interface elements are displayed at one or more of the determined screen locations, including overlaying a browser-based text box user output interface element over the email text box user output interface element;

receiving encrypted text from the web-based email system;

decrypting the encrypted text from the web-based email system; and

transferring the decrypted text into one or more elements of the browser-based user interface.

16. The method of claim 15, wherein decrypting the encrypted text from the web-based email system comprises decrypting using a key derived from a master secret from a key server, the key further being derived from an identifier identifying a sender of the email message and from an identifier identifying the receiver of the email message.

17. The method of claim 15, wherein decrypting the encrypted text from the web-based email system comprises:

requesting a key from a key server, the request from the key server comprising an identification of a sender of the email message and an identification of the recipient of the email message;

receiving a sender-recipient key from the key server, wherein the sender-recipient key is derived from a master secret, the identification of a sender of the email message and the identification of the recipient of the email message.

18. The method of claim 15, wherein receiving encrypted text from the web-based email system comprises receiving encrypted text in an attachment to an email.

19. At a web browser in a computing system, a method of encrypting data for a web page based user interface, the method comprising:

receiving user input requesting a web page user interface for a web-based application;

requesting the web page user interface from a server for the web-based application;

receiving web page code from the server for the web page user interface;

parsing the web page code for the web page user interface to determine screen locations of one or more user input interface elements;

rendering the web page user interface in the browser;

overlaying one or more browser-based interface elements implemented integral to the browser and separate from the web page code from the server onto the web page user interface, wherein one or more of the browser-based interface elements are displayed at one or more of the determined screen locations;

receiving user input in one or more of the browser-based interface elements;

encrypting the user input received in the browser-based interface elements;

transferring the encrypted user input into one or more elements of the web page user interface.