Dynamic, selective obfuscation of information for multi-party transmission

• US 8,824,684 B2
• Filed: 12/08/2007
• Issued: 09/02/2014
• Est. Priority Date: 12/08/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Calcaterra, Jeffrey A., Hind, John R., Salahshour, Abdolreza
• Primary Examiner(s): Zand, Kambiz
• Assistant Examiner(s): NGUYEN, TRONG H
• Application Number:
  US11/953,033
• Publication Number:
  US 20090147958A1
• Time in Patent Office: 2,460 Days
• Field of Search: None
• US Class Current: 380/278
• CPC Class Codes: H04L 2209/16 Obfuscation or hiding, e.g. involving white box
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0833 involving conference or group key network architectures or network communication protocols for key management in group communication in a packet data network H04L63/065

Abstract

Selectively obfuscating, or obscuring, a portion or portions of information in a multi-party transmission. A user participating in a multi-party exchange signals a communication device (or proxy) that he will provide private information that is to be perceptible only to a subset of the other participants. This user also identifies that subset, preferably by providing a group identifier for a group in which that subset of participants are members. The communication device transmits a member-specific descriptor comprising an encrypted version of a group key, and uses this group key to encrypt the private information that is to be perceptible only to the subset. Device-specific characteristics of participant devices are used, in addition to user-provided data (such as a user'"'"'s log-on identifier and/or password), as input to create cryptographic key information. Only participants in the subset can decrypt the encrypted private information; other participants preferably receive a filler pattern instead.

Claims

1. A computer-implemented method of selectively obfuscating information in a multi-party voice communication, comprising using a processor of a computer for:

receiving a signal, during an ongoing multi-party voice communication, from a device with which a selected one of a plurality of participants is participating in the multi-party voice communication, the signal indicating that a next utterance from the selected participant is to be transmitted as an obfuscated segment in the ongoing multi-party voice communication; and

responding to the signal, during the ongoing multi-party voice communication, comprising;

determining, from among the plurality of participants, a subset of the participants selected to perceive the obfuscated segment;

using a participant-specific encryption key, for each of the subset of participants, to encrypt a group-specific decryption key;

creating, from the encrypted group-specific decryption key for each of the subset of participants, a descriptor structure in which the encrypted group-specific decryption key for each of the participants in the subset is identified with a corresponding identifier of the participant;

obfuscating the next utterance as an obfuscated segment by encrypting the next utterance using a group-specific encryption key that corresponds to the group-specific decryption key; and

transmitting the obfuscated segment, and the descriptor structure, to each of the plurality of participants in the multi-party voice communication, thereby enabling each of the participants in the subset to decrypt and perceive the obfuscated segment while preventing remaining ones of the participants of the multi-party voice communication from decrypting and perceiving the obfuscated segment.

2. The method according to claim 1, wherein the transmission of the obfuscated segment occurs on a data channel used for transmitting all segments of the multi-party voice communication and the transmission of the descriptor structure occurs on a control channel of the multi-party voice communication.

3. The method according to claim 1, wherein at least one segment transmitted to the plurality of participants of the multi-party voice communication prior to the transmitting of the obfuscated segment is not obfuscated and is therefore perceptible to all of the plurality of participants.

4. The method according to claim 1, wherein the group-specific decryption key comprises a symmetric key that is recoverable, for decrypting the obfuscated segment, at a device used by each of the participants in the subset but is not recoverable at a device used by any of the remaining ones of the participants.

5. The method according to claim 1, wherein the signal is received, from the device with which the selected one of the participants is participating, responsive to the selected one activating a predetermined key sequence on the device.

6. The method according to claim 1, wherein each of the participants in the subset is enabled to perceive the next utterance, responsive to recovering the group-specific decryption key from the transmitted descriptor structure using a participant-specific decryption key that corresponds to the participant-specific encryption key of the participant and using the recovered group-specific decryption key to decrypt the obfuscated segment, and each of the remaining ones of the participants is provided with a filler pattern to perceive in place of perceiving the next utterance.

7. The method according to claim 1, wherein the signal serves to dynamically identify the utterance during the multi-party voice communication.

8. The method according to claim 7, wherein the device with which the selected one of the participants is participating comprises a phone device.

9. The method according to claim 1, wherein the multi-party voice communication is a multi-party push-to-talk communication and the next utterance is a dynamically-identified spoken message that is spoken during the multi-party push-to-talk communication.

10. The method according to claim 1, wherein:

the group-specific decryption key is a symmetric key that is identical to the group-specific encryption key; and

the symmetric key is made specific to a particular session of the multi-party voice communication by combining a session-specific identifier of the multi-party voice communication with a group-specific symmetric key that is associated with the subset.

11. The method according to claim 10, wherein:

the multi-party voice communication comprises a conference call; and

the session-specific identifier comprises a conference call-in passcode of the conference call.

12. The method according to claim 1, wherein the multi-party voice communication is transmitted over a data network.

13. The method according to claim 12, wherein the data network comprises a Voice Over Internet Protocol network.

14. The method according to claim 1, wherein responding to the signal continues until receiving a next signal from the selected one of the participants, the next signal indicating that subsequent utterances from the selected one are to be transmitted as un-obfuscated segments in the ongoing multi-party voice communication.

15. A method of selectively obfuscating information in a multi-party voice communication, comprising using a processor of a computer for:

receiving a signal, during an ongoing multi-party voice communication, from a device with which a selected one of a plurality of participants is participating in the multi-party voice communication, the signal indicating that a next utterance from the selected participant is to be treated as a private segment in the ongoing multi-party voice communication; and

responding to the signal, during the ongoing multi-party voice communication, comprising;

determining a subset of the plurality of participants in the multi-party voice communication who are to receive, in a perceptible form, the private segment;

obfuscating the private segment by encryption using a group key corresponding to the subset;

encrypting a copy of the group key for each of the participants in the subset, such that the group key is only recoverable by each of the participants in the subset using the participant'"'"'s encrypted copy of the group key and is not recoverable, from any of the encrypted copies of the group key, by any of the participants not in the subset;

creating, from the encrypted copies of the group key, a descriptor structure in which the encrypted copy of the group key for each of the participants in the subset is identified with a corresponding identifier of the participant; and

transmitting the obfuscated private segment, and the descriptor structure, to all of the plurality of the participants in the multi-party voice communication, whereby each of the participants in the subset can decrypt the transmitted obfuscated private segment, upon receipt thereof, using the group key recovered by the participant from the participant'"'"'s encrypted copy of the group key in the descriptor structure but none of the participants not in the subset can decrypt the transmitted obfuscated private segment upon receipt thereof.

16. The method according to claim 15, wherein:

a session-specific identifier of the multi-party voice communication is associated with each separate session of the multi-party voice communication, and is known to each of the plurality of participants in the multi-party voice communication;

the obfuscating further comprises combining the group key corresponding to the subset with the session-specific identifier of the multi-party voice communication to create a session-specific version of the group key, and using the session-specific version of the group key to encrypt the private segment; and

each of the participants in the subset can decrypt the transmitted obfuscated segment, upon receipt of the transmitted obfuscated segment and the descriptor structure, using the session-specific version of the group key after recreating a local copy of the session-specific version of the group key by combining the group key recovered by the participant from the participant'"'"'s encrypted copy of the group key in the descriptor structure with the session-specific identifier of the multi-party voice communication.

17. A computer program product for selectively obfuscating information in a multi-party voice communication, the computer program product embodied on one or more non-transitory computer-usable storage media and comprising computer-usable program code for:

receiving a signal, during an ongoing multi-party voice communication, from a device with which a selected one of a plurality of participants is participating in the multi-party voice communication, the signal indicating that a next utterance from the selected participant is to be treated as a private segment in the ongoing multi-party voice communication; and

responding to the signal, during the ongoing multi-party voice communication, comprising;

determining a subset of the plurality of participants in the multi-party voice communication who are to receive, in a perceptible form, the private segment;

obfuscating the private segment by encryption using a group key corresponding to the subset;

encrypting a copy of the group key for each of the participants in the subset, such that the group key is only recoverable by each of the participants in the subset with the participant'"'"'s encrypted copy of the group key and is not recoverable, from any of the encrypted copies of the group key, by any of the participants not in the subset;

creating, from the encrypted copies of the group key, a descriptor structure in which the encrypted copy of the group key for each of the participants in the subset is identified with a corresponding identifier of the participant; and

transmitting the obfuscated private segment, and the descriptor structure, to all of the plurality of the participants in the multi-party voice communication, whereby each of the participants in the subset can decrypt the transmitted obfuscated private segment, upon receipt thereof, using the group key recovered by the participant from the participant'"'"'s encrypted copy of the group key in the descriptor structure but none of the participants not in the subset can decrypt the transmitted obfuscated private segment upon receipt thereof.

18. The computer program product according to claim 17, wherein the obfuscated segment has associated therewith an expiration timestamp, and wherein the transmitted obfuscated segment cannot be decrypted by any of the participants in the multi-party voice communication after the expiration timestamp expires.

19. The computer program product according to claim 17, wherein:

the encrypting a copy of the group key for each of the participants in the subset uses a participant-specific public key; and

for each of the participants in the subset, the participant'"'"'s encrypted copy of the group key is recovered from the descriptor structure using a participant-specific private key that corresponds to the participant-specific public key.

20. The computer program product according to claim 19, wherein the participant-specific private key for each of the participants in the subset is encrypted, at a device currently used by the participant for participating in the multi-party voice communication, with a symmetric encryption key created by combining hardware-specific information which uniquely corresponds to the currently-used device in combination with data provided by the participant and which is not transmitted to any of the participants in the multi-party voice communication, thereby enabling the participant-specific private key to be secured for storing at the currently-used device.

21. A system for selectively obfuscating information in a multi-party voice communication, comprising a computer comprising a processor and instructions which are executable, using the processor of the computer, for implementing functions comprising:

receiving a signal, during an ongoing multi-party voice communication, from a device with which a selected one of a plurality of participants is participating in the multi-party voice communication, the signal indicating that a next utterance from the selected participant is to be transmitted as an obfuscated segment in the ongoing multi-party voice communication; and

responding to the signal, during the ongoing multi-party voice communication, comprising;

determining, from among the plurality of participants, a subset of the participants selected to perceive the obfuscated segment;

using a participant-specific encryption key, for each of the subset of participants, to encrypt a group-specific decryption key;

creating, from the encrypted group-specific decryption key for each of the subset of participants, a descriptor structure in which the encrypted group-specific decryption key for each of the participants in the subset is identified with a corresponding identifier of the participant;

obfuscating the next utterance as an obfuscated segment by encrypting the next utterance using a group-specific encryption key that corresponds to the group-specific decryption key; and

transmitting the obfuscated segment, and the descriptor structure, to each of the plurality of participants in the multi-party voice communication, thereby enabling each of the participants in the subset to decrypt and perceive the obfuscated segment while preventing remaining ones of the participants of the multi-party voice communication from decrypting and perceiving the obfuscated segment.

22. The system according to claim 21, wherein the group-specific encryption key is a symmetric key and is identical to the group-specific decryption key.