Systems and methods for conducting secure VOIP multi-party calls

• US 10,715,557 B2
• Filed: 09/13/2018
• Issued: 07/14/2020
• Est. Priority Date: 05/29/2015
• Status: Active Grant

• Current Assignee: Nagravision SA (Kudelski SA)
• Original Assignee: Nagravision SA (Kudelski SA)
• Inventors: Fer, Francois, Macchetti, Marco, Gauteron, Laurent, Perrine, Jerome
• Primary Examiner(s): Poltorak, Piotr
• Application Number:
  US16/130,828
• Publication Number:
  US 20190028518A1
• Time in Patent Office: 670 Days
• Field of Search: None
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/065 for group communications cryptographic mechanisms or cryptographic arrangements for key management involving conference or group key H04L9/0833
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 12/61 Time-dependent

Abstract

System and method for establishing secure conference calls. In one example system, a central conference call server establishes point-to-point connections with accessory devices comprising a secure element and connected to corresponding participant devices. The conference call server includes an interface to a plurality of secure elements configured to perform scrambling and unscrambling of media signals communicated to and from the accessory devices. In another example, one of the participant devices operates as the central conference call server. In other examples, participant devices communicate on a conference call via point-to-point connections between all accessory devices connected to the participant devices. The accessory devices include secure elements for decryption and encryption of media signals communicated between the accessory devices.

Claims

1. A method comprising:

receiving, by a conference-call server, a plurality of data packets sent from each of a plurality of remote endpoints, each of the plurality of data packets being in a conference-call session;

relaying each of the received data packets over a physical-connection port to a respective secure hardware element of a plurality of secure hardware elements associated with the conference-call server;

establishing respective cryptographic relationships between each of the plurality of respective secure hardware elements and each of the plurality of respective remote endpoints at least in part by negotiating, using the each of the plurality of respective secure hardware elements, respective endpoint-specific cryptographic key information for the conference call session with the each of the plurality of respective remote endpoints;

decrypting an encrypted packet payload of each relayed data packet;

mixing decrypted audio from each decrypted packet payload to generate unencrypted mixed audio;

encrypting the unencrypted mixed audio; and

outputting the encrypted mixed audio for transmission to the respective remote endpoint.

2. The method of claim 1, further comprising:

receiving, by the conference-call server, a secure communication connection initiation request from each remote endpoint of the plurality of remote endpoints,

wherein establishing the respective cryptographic relationships includes relaying key information from the respective remote endpoint to the corresponding secure hardware element of the plurality of secure hardware elements and is in response to receiving the respective secure communication connection initiation request.

3. The method of claim 2, wherein establishing the respective cryptographic relationships comprises performing a key exchange to generate, for each secure hardware element of the plurality of secure hardware elements, a server decryption key for decrypting the encrypted packet payload and a server encryption key for encrypting the mixed audio.

4. The method of claim 3, wherein performing the respective key exchange comprises a Diffie-Hellman key exchange.

5. The method of claim 1, further comprising:

receiving a global key from each remote endpoint of the plurality of remote endpoints; and

authenticating the global key at least in part by determining whether the global key is valid for use to participate in the conference-call session.

6. The method of claim 5, wherein authenticating the global key further comprises determining whether the global key is valid for a time and day on which a request for the global key is received.

7. The method of claim 5, further comprising:

receiving, at the conference-call server, a request for the global key from one of the remote endpoints for participation in the conference-call session;

retrieving the global key from a key-management database; and

sending the global key to the requesting remote endpoint.

8. The method of claim 1, further comprising:

receiving a segment key indicative of a group to which a user of the corresponding remote endpoint belongs; and

authenticating the corresponding segment key by determining whether the corresponding segment key is valid for use to participate in the conference-call session.

9. The method of claim 1, further comprising:

receiving a segment-key request for a segment key from one of the remote endpoints corresponding to a group to which a user of at least one other remote endpoint belongs;

retrieving the segment key from a key-management database; and

sending the segment key to the requesting remote endpoint.

20. The method of claim 1, wherein each of the respective cryptographic relationships is associated with security parameters that (i) include the cryptographic key information, and (2) are inaccessible to a communication interface.

10. A conference-call server comprising:

a communication interface configured to communicate, during a conference-call session, a plurality of data packets to a plurality of remote endpoints of the conference-call session;

a cryptographic interface coupled to the communication interface, the cryptographic interface comprising a plurality of individual physical-connection ports, each connected to a secure hardware element of a plurality of secure hardware elements associated with the conference-call server, the cryptographic interface configured to receive the respective data packets sent from the respective remote endpoints and to relay the respective data packets to the respective secure hardware elements;

each secure hardware element configured to;

establish respective cryptographic relationships between each of the plurality of respective secure hardware elements and the respective remote endpoint at least in part by negotiating, using the each of the plurality of respective secure hardware elements, respective endpoint-specific cryptographic key information for the conference call session with the each of the plurality of respective remote endpoints; and

decrypt an encrypted packet payload of each relayed data packet; and

an audio mixer configured to mix decrypted audio from each decrypted packet payload to generate unencrypted mixed audio,

wherein each secure hardware element is further configured to encrypt the unencrypted mixed audio, and

wherein the cryptographic interface is further configured to output the encrypted mixed audio for transmission to the respective remote endpoint.

11. The conference-call server of claim 10, wherein the respective secure hardware elements of the plurality of secure hardware elements comprise respective microSD cards.

12. The conference-call server of claim 10, wherein the cryptographic interface is a hardware interface to the plurality of secure hardware elements selected from the group consisting of:

a smart card interface, a ball grid array (“

BGA”

) interface, a surface mount device (“

SMD”

) interface, and a printed circuit board (“

PCB”

) interface.

13. The conference-call server of claim 10, wherein the cryptographic key information of each secure hardware element of the plurality of secure hardware elements comprises a server encryption key and a server decryption key, each respective key being generated using a key-exchange performed during establishment of the respective cryptographic relationship using key information received from the respective remote endpoint, wherein the server decryption key is used to decrypt the encrypted packet payload and the server encryption key is used to encrypt the mixed audio.

14. The conference-call server of claim 13, wherein the respective key-exchanges comprise Diffie-Hellman key-exchanges.

15. The conference-call server of claim 10, further comprising a remote-endpoint-authentication module configured to authenticate a global key provided by a given remote endpoint of the plurality of remote endpoints during initiation of secure media session with the conference-call server.

16. The conference-call server of claim 15, wherein the remote-endpoint-authentication module is further configured to validate a date and time associated with the global key.

17. The conference-call server of claim 15, wherein the remote-endpoint-authentication module is further configured to validate a segment key provided by a given remote endpoint in the plurality of remote endpoints during initiation of the corresponding secure media session with the conference-call server, the segment key being indicative of a group identity of a user of the given remote endpoint.

18. The conference-call server of claim 15, further comprising a key-management database configured to maintain the global key and to provide the global key to requesting remote endpoints during respective registration processes.

19. The conference-call server of claim 18, wherein the key-management database is further configured to:

maintain a segment key having a value indicative of a group identity; and

provide the segment key to at least one of the remote endpoints during the respective registration process.