System and method for communicating confidential messages

• US 8,266,452 B2
• Filed: 06/01/2005
• Issued: 09/11/2012
• Est. Priority Date: 06/01/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Dunn, Paul M., Belcher, Aaron J., Gatzke, Alan D.
• Primary Examiner(s): Pwu, Jeffrey
• Assistant Examiner(s): Brown, Anthony
• Application Number:
  US11/143,240
• Publication Number:
  US 20060274856A1
• Time in Patent Office: 2,659 Days
• Field of Search: 713/193
• US Class Current: 713/193
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 63/045 wherein the sending and receiving network entities apply hybrid encryption, i.e. combination of symmetric and asymmetric encryption cryptographic mechanisms or cryptographic arrangements using a plurality of keys or algorithms H04L9/14
• CPC Class Codes: H04L 9/0825 using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
• CPC Class Codes: H04M 3/533 Voice mail systems

Abstract

A method of recording messages includes recording audio data in a first file structured in accordance with a file format that defines a first portion and a second portion. The audio data is recorded in the first portion of the first file. The method also includes encrypting the audio data stored in the first portion of the first file and generating a second file structured according to the file format. The second file includes decoy audio data in the first portion of the second file and the encrypted audio data in the second portion of the second file. The decoy audio data indicates a confidential status of the second file or serves as a red herring to distract from the encrypted audio data in the second portion of the second file.

Claims

1. A method of recording messages comprising:

recording, with a processor, audio data associated with a call in a first file structured in accordance with a file format that defines a first portion and a second portion, wherein the audio data is recorded in the first portion of the first file;

receiving one or more recipient identifiers from a caller associated with the call, the recipient identifiers identifying one or more recipients of the audio data;

identifying, based on the one or more recipient identifiers received from the caller, one or more public keys associated with the one or more recipients of the audio data;

encrypting, with the processor, the audio data stored in the first portion of the first file based on the identified one or more public keys; and

generating, with the processor, a second file structured according to the file format that includes decoy audio data in the first portion of the second file and the encrypted audio data in the second portion of the second file, wherein the decoy audio data indicates a confidential status of the second file.

2. The method of claim 1, wherein the decoy audio data is readable by media players operable to read files formatted according to the file format.

3. The method of claim 1, wherein generating the second file comprises generating a second file that includes decoy audio data in the first portion, wherein the decoy audio data is associated with a recorded message that indicates the confidential status of the second file when read by a media player operable to read files structured in accordance with the file format.

4. The method of claim 1, wherein encrypting the audio data comprises:

encrypting the audio data using a session key; and

encrypting the session key using the one or more identified public keys; and

wherein generating the second file comprises generating a second file that includes the encrypted session key.

5. The method of claim 1,

wherein encrypting the audio data comprises:

encrypting the audio data using a session key; and

encrypting a copy of the session key using each of the one or more identified public keys; and

wherein generating the second file comprises generating a second file that includes each of the encrypted session keys.

6. The method of claim 1, wherein recording the audio data in a first file structured in accordance with a file format comprises recording the audio data in a RIFF file.

7. The method of claim 1, further comprising transmitting the second file to a voicemail server associated with a recipient of the audio data.

8. The method of claim 1, further comprising storing the second file and associating the second file with a voicemail account associated with an intended recipient of the audio data.

9. The method of claim 1, wherein recording the audio data comprises:

receiving a plurality of packets comprising audio data associated with audio signals; and

ordering the packets;

storing audio data from the ordered packets in the first portion of the first file.

34. The method of claim 1, wherein the decoy audio data indicates a confidential status of the second file by indicating to a party that is not included among a selected one or more recipients of the second file that the second file is a confidential message.

35. The method of claim 1, wherein the decoy audio data is designed to sound like a voicemail message.

10. A method of recording messages comprising:

accessing, with a processor, encrypted audio data associated with a call and stored in a first file structured in accordance with a file format that defines a first portion and a second portion, the encrypted audio data encrypted with one or more public keys identified based on one or more recipient identifiers, the recipient identifiers received from a caller associated with the audio data and identifying one or more recipients of the call, wherein decoy audio data is stored in the first portion of the first file and the encrypted audio data is stored in the second portion of the first file, the decoy audio data indicating a confidential status of the second file;

decrypting, with the processor, the encrypted audio data; and

generating, with the processor, a second file that includes the decrypted audio data, wherein the second file is structured according to the file format, and wherein the decrypted audio data is stored in the first portion of the second file.

11. The method of claim 10, wherein the decoy audio data is readable by media players operable to read files formatted according to the file format.

12. The method of claim 10, wherein the first file includes an encrypted session key and wherein decrypting the audio data comprises:

identifying a private key associated with a recipient of the audio data;

decrypting the encrypted session key using the identified private key; and

decrypting the audio data stored in the second portion using the decrypted session key.

13. The method of claim 10, wherein accessing the encrypted audio data stored in the first file comprises accessing encrypted audio data stored in a WAV file, and wherein the first portion comprises a first Resource Interchange File Format (RIFF) block and the second portion comprises at least one additional RIFF block.

14. The method of claim 10, wherein accessing the first file comprises receiving the first file.

15. The method of claim 10, further comprising storing the second file in a voicemail account associated with an intended recipient of the audio data.

16. The method of claim 10, wherein recording the message comprises:

receiving a plurality of packets comprising information associated with audio signals;

ordering the packets; and

storing the ordered packets in the first portion of the first file.

17. A device for recording messages comprising:

a memory operable to store processor instructions; and

a processor operable to;

record audio data associated with a call in a first file structured in accordance with a file format that defines a first portion and a second portion, wherein the audio data is recorded in the first portion of the first file;

receive one or more recipient identifiers from a caller associated with the call, the recipient identifiers identifying one or more recipients of the audio data;

identify, based on the one or more recipient identifiers received from the caller, one or more public keys associated with the one or more recipients of the audio data;

encrypt the audio data stored in the first portion of the first file based on the identified one or more public keys; and

generate a second file structured according to the file format that includes decoy audio data in the first portion of the second file and the encrypted audio data in the second portion of the second file, the decoy audio data indicating a confidential status of the second file.

18. The device of claim 17, wherein the decoy audio data is readable by media players operable to read files formatted according to the file format.

19. The device of claim 17, wherein the processor is operable to generate a second file that includes decoy audio data that is associated with a recorded message, the recorded message indicating the confidential status of the second file when read by a media player operable to read files structured in accordance with the file format.

20. The device of claim 17, wherein the processor is operable to encrypt the audio data by:

encrypting the audio data using a session key; and

encrypting the session key using the one or more identified public keys; and

wherein generating the second file comprises generating a second file that includes the encrypted session key.

21. The device of claim 17,

wherein the processor is operable to encrypt the audio data by:

encrypting the audio data using a session key; and

encrypting a copy of the session key using each of the one or more identified public keys; and

wherein generating the second file comprises generating a second file that includes each of the encrypted session keys.

22. The device of claim 17, wherein the processor is operable to record the audio data in a first file structured in accordance with a file format by recording the audio data in a RIFF file.

23. The device of claim 17, wherein the processor is further operable to transmit the second file to a voicemail server associated with a recipient of the audio data.

24. The device of claim 17, wherein the processor is further operable to store the second file in the memory and to associate the second file with a voicemail account associated with an intended recipient of the audio data.

25. The device of claim 17, wherein the processor is operable to record the audio data by:

receiving a plurality of packets comprising audio data associated with audio signals; and

ordering the packets;

storing audio data from the ordered packets in the first portion of the first file.

26. A device for recording messages comprising:

a memory operable to store processor instructions; and

a processor operable to;

access encrypted audio data associated with a call and stored in a first file structured in accordance with a file format that defines a first portion and a second portion, the encrypted audio data encrypted with one or more public keys identified based on one or more recipient identifiers, the recipient identifiers received from a caller associated with the audio data and identifying one or more recipients of the call, wherein decoy audio data is stored in the first portion of the first file and the encrypted audio data is stored in the second portion of the first file, and wherein the decoy audio data indicates a confidential status of the first file;

decrypt the encrypted audio data; and

generate a second file that includes the decrypted audio data, wherein the second file is structured according to the file format, and wherein the decrypted audio data is stored in the first portion of the second file.

27. The device of claim 26, wherein the first file includes an encrypted session key and wherein the processor is operable to decrypt the audio data by:

identifying a private key associated with a recipient of the audio data;

decrypting the encrypted session key using the identified private key; and

decrypting the audio data stored in the second portion using the decrypted session key.

28. The device of claim 26, wherein the processor is operable to access the encrypted audio data stored in the first file structured by accessing encrypted audio data stored in a WAV file, and wherein the first portion comprises a first Resource Interchange File Format (RIFF) block and the second portion comprises at least one additional RIFF block.

29. The device of claim 26, wherein the processor is operable to access the first file by receiving the first file.

30. The device of claim 26, the processor is further operable to store the second file in a voicemail account associated with an intended recipient of the audio data.

31. The device of claim 26, wherein the processor is operable to record the message by:

receiving a plurality of packets comprising information associated with audio signals;

ordering the packets; and

storing the ordered packets in the first portion of the first file.

32. A system for recording messages comprising:

means for recording audio data associated with a call in a first file structured in accordance with a file format that defines a first portion and a second portion, wherein the audio data is recorded in the first portion of the first file;

means for receiving one or more recipient identifiers from a caller associated with the call, the recipient identifiers identifying one or more recipients of the audio data;

means for identifying, based on the one or more recipient identifiers received from the caller, one or more public keys associated with the one or more recipients of the audio data;

means for encrypting the audio data stored in the first portion of the first file based on the identified one or more public keys; and

means for generating a second file structured according to the file format that includes decoy audio data in the first portion of the second file and the encrypted audio data in the second portion of the second file, the decoy audio data indicating a confidential status of the second file.

33. A system for recording messages comprising:

means for accessing encrypted audio data associated with a call and stored in a first file structured in accordance with a file format that defines a first portion and a second portion, wherein decoy audio data is stored in the first portion of the first file and the encrypted audio data is stored in the second portion of the first file, the encrypted audio data encrypted with one or more public keys identified based on one or more recipient identifiers, the recipient identifiers received from a caller associated with the audio data and identifying one or more recipients of the call, the decoy audio data indicating a confidential status of the first file;

means for decrypting the encrypted audio data; and

means for generating a second file that includes the decrypted audio data, wherein the second file is structured according to the file format, and wherein the decrypted audio data is stored in the first portion of the second file.