The invention relates generally to secure communication. More particularly, the invention relates to a method and system for establishing a secure communication session with third-party access at a later time.
Automated key negotiation is the most prevalent form of key management deployed in the Internet today. Typically, automated key negotiation employs Internet Key Exchange (IKE) (or other similar protocols) which is the key management protocol associated with the Internet Protocol Security (IPSec) standard or Secure Sockets Layer (SSL) protocol. Key distribution protocols are often used with key management through a centralized server and in group security applications.
The IKE protocol is the automated key management protocol used to establish IPsec key or Security Association (SA). The SA, or the policy and parameters governing the algorithms and processes used to protect IPsec communication, is negotiated. The key is derived from unique information or nonces shared by the two devices after mutual authentication and from Diffie-Hellman parameters as is known in the art. In some instances the two devices include a client and a server and in other instances the two devices include two peers as is shown in
Using contributory key establishment protocols such as those described above, both devices contribute secret data for computation of the data protection keys. As an example in which a device A wants to establish a secure communication session with each of devices B and C, device A supplies one value to device B and a different value to device C. Devices B and C each contribute a different value and therefore the security key resulting from the applied protocol for the communication between devices A and B is different from the security key generated for communication between devices A and C. Even if device A supplied the same value to device B and device C, the security key for communication between device A and device B would be different than the security key for communication between device A and device C.
Other secure communication configurations such as a center facilitated two-party secure communication, a one-to-many secure communication or a many-to-many secure communication require that a single SA and keys be downloaded to two or more devices. The SSL and IKE protocols described above do not accommodate such configurations. Instead, other protocols such as Group Domain of Interpretation (GDOI) and Multimedia Internet Keying (MIKEY) protocols are often used. The GDOI and MIKEY protocols use a trusted third party or an asymmetric server-client relationship for key establishment. The client contacts the server for keys and, after mutual authentication, the server unilaterally determines the security policy and sends the keys. In some instances multi-party negotiation does not converge or may not otherwise be practical for establishing a secure communication. The client is not involved in determining the security parameters of the current connection. In some instances the client may reject the policy and keys, and abstain from participating in the secure communication.
What is needed is a method for key negotiation and key distribution that avoids the above-described problems. The present invention satisfies this need and provides additional advantages.
In one aspect, the invention features a method for establishing a secure communication session with third-party access at a later time. A first communication subsession is established between two original devices using a first key generated by a two-party key and security association protocol. One of the original devices is established as a group key server. A request from a joining device to join the secure communication session is received and a second communication subsession is established between the original devices using a second key generated by the two-party key and security association protocol. The second key is provided to the joining device to enable participation in the second communication subsession.
In another aspect, the invention features a method for establishing a secure communication session with third-party access at a later time. A first communication subsession is established between a first original device and a second original device using a first key generated by a two-party key and security association protocol. The first original device receives a request to join the secure communication session from a first joining device and the second original device receives a request to join the secure communication session from a second joining device. Credentials of the first and second joining devices are verified for authorization to join the secure communication session. A second communication subsession between the first and second original devices is established using a second key generated by the two-party key and security association protocol. The first original device and the second original device download the second key to the first joining device and the second joining device, respectively, to enable participation by the first and second joining devices in the second communication subsession.
In yet another aspect, the invention features a system for establishing a secure communication session enabling third-party access at a later time. The system includes a first original device and a second original device each configured to establish a first communication subsession with the other original device using a first key generated by a two-party key and security association protocol. The first original device is adapted to receive a request to participate in the secure communication session from a joining device and to generate and download a group key for a second communication subsession to the joining device in response thereto.
The above and further advantages of this invention may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in the various figures. For clarity, not every element may be labeled in every figure. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
In brief overview, the invention relates to a method for establishing a secure communication session with third-party access at a later time. The method allows two devices to maintain an existing key establishment channel in a point-to-point manner without interruption while allowing other devices to join a secure communication session. As used herein, a device means any telecommunication device capable of transmitting and receiving communications data to and from one or more other telecommunication devices. For example, a device can be a personal computer, laptop computer, cellular phone, video phone, personal digital assistant and the like. At least one of the devices is capable of performing as a group server for distribution of a group key.
The method is seamless; there is no requirement to “tear-down” the pre-existing secure session and to re-establish a new secure connection between the original devices. Moreover, the ability in some instances to have each of the original devices perform as a group server improves efficiency in comparison to a single group server configuration. In particular, distribution of key resources is improved, especially for large groups where “keying” is a function of membership. Advantageously, the method enables the coordination of download-based key distribution with contributory key establishment devices and provides seamless expansion of security from a unicast secure session to a multicast secure session. The method is particularly beneficial to conferencing sessions and other applications in which multicast communication is utilized. The method also accommodates devices that are only capable of point-to-point secure communication.
Voice communication, video communication, video distribution (e.g., online meeting video conferencing) and chat services are examples of applications in which a secure communication session can be established between two devices. One or more additional devices may desire to join the secure communication session at a later time.
Before initiating the group security protocol, original devices A and B re-key (step 140) as shown in
The joining devices C and D are expected to run the group key protocol utilized by the group key server. The group key server verifies (step 150) the credentials of the joining devices and downloads (step 160) the new group key. Credentials used for authentication and authorization can include a password or a certificate as known in the art. Potentially other supporting keys required by a particular group key distribution protocol are also downloaded. Subsequent secure communication between all participating devices is shown in
In an alternative embodiment, one of the original devices A and B allows a joining device C or D to join the secure communication session. The joining device C or D can understand that it is part of a group; however, the original device A or B can continue to operate in a single (i.e., point-to-point) mode using the original key KEY 1 or the new key KEY 2.
In the embodiment described according to
Joining devices can request to join the session at different times. Referring to
Although
While the invention has been shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
This application claims the benefit of U.S. provisional patent application Ser. No. 60/669,624, filed Apr. 8, 2005, titled “Synthesis of Key Negotiation and Management”, the entirety of which provisional application is incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
6941457 | Gundavelli et al. | Sep 2005 | B1 |
7127613 | Pabla et al. | Oct 2006 | B2 |
7234058 | Baugher et al. | Jun 2007 | B1 |
7310730 | Champagne et al. | Dec 2007 | B1 |
7395423 | Dondeti et al. | Jul 2008 | B1 |
20030093669 | Morais et al. | May 2003 | A1 |
20030149874 | Balfanz et al. | Aug 2003 | A1 |
20030163697 | Pabla et al. | Aug 2003 | A1 |
20050210252 | Freeman et al. | Sep 2005 | A1 |
20060173940 | Guntupalli et al. | Aug 2006 | A1 |
20060224893 | Sales et al. | Oct 2006 | A1 |
20060294378 | Lumsden et al. | Dec 2006 | A1 |
20080313464 | Fascenda et al. | Dec 2008 | A1 |
20100002880 | Yoon et al. | Jan 2010 | A1 |
20100030982 | Sela et al. | Feb 2010 | A1 |
20100121934 | Guntupalli et al. | May 2010 | A1 |
Number | Date | Country | |
---|---|---|---|
20070198836 A1 | Aug 2007 | US |
Number | Date | Country | |
---|---|---|---|
60669624 | Apr 2005 | US |