Secure telecommunications

• US 5,455,861 A
• Filed: 08/27/1993
• Issued: 10/03/1995
• Est. Priority Date: 12/09/1991
• Status: Expired due to Term

• Current Assignee: AT&T IPM Corp. (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Faucher, David W., Maher, David P., Kaplan, Michael M., Heer, Daniel N.
• Primary Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US08/113,155
• Time in Patent Office: 767 Days
• Field of Search: 380/52, 380/41, 380/9, 380/18, 379/442, 379/95
• US Class Current: 380/266
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges

Abstract

A security node disposed in the telecommunications network connecting calling and called parties transforms information (which can be voice, data, facsimile, video and other types of calls or messages) encrypted in a first format to (a) encrypted information in a different format or to (b) non-encrypted information, and vice-versa. The node is accessible from any location connected to the network. By routing calls or messages originated by the calling party and destined for the called party via the security node, and providing appropriate control signals to the node, the information may be encrypted only over a portion of the transmission path between the parties, and clear over the remainder of the transmission path. Alternatively, the information may be encrypted in different portions of the path using different encryption algorithms. This arrangement enables the parties to obtain relatively secure communications even if only one party has a security device at the originating or terminating end, or if the parties have security devices using different handshaking protocols and encryption algorithms.

Claims

1. An apparatus for providing secure communication of information signals over a communications network, the apparatus for coupling between a telephone base and an information signal generator, the telephone base coupled to the communications network, the apparatus comprising a signal encryptor for coupling to the information signal generator and the telephone base, the signal encryptor for generating encrypted signals reflecting signals formed by the generator, the telephone base for transmitting over the network signals reflecting the generated encrypted signals.

2. The apparatus of claim 1 further comprising a speech coder for coupling to the information signal generator and coupled to the signal encryptor, the speech coder for generating coded speech signals reflecting speech signals formed by the generator, such that the signal encryptor generates encrypted signals which reflect the coded speech signals.

3. The apparatus of claim 1 further comprising a modulator coupled to the signal encryptor and for coupling to the telephone base, the modulator for generating modulated signals reflecting encrypted signals generated by the signal encryptor, wherein the signals transmitted by the telephone base reflect the modulated signals.

4. The apparatus of claim 1 further comprising a telephone base interface coupled to the signal encryptor and for coupling to the telephone base, the telephone base interface for adapting the apparatus for operation with the telephone base.

5. The apparatus of claim 1 further comprising an information signal generator interface coupled to the signal encryptor and for coupling to the information signal generator, the information signal generator interface for adapting the apparatus for operation with the information signal generator.

6. The apparatus of claim 1 wherein the information signal generator is a microphone.

7. The apparatus of claim 1 wherein the information signal generator is a fax machine.

8. The apparatus of claim 1 wherein the information signal generator is a computer.

9. The apparatus of claim 1 further for coupling between a telephone base and a decrypted signal utilization device and further comprising a signal decryptor for coupling to the utilization device and the telephone base, the signal decryptor for generating decrypted signals to be provided to the utilization device, the decrypted signals reflecting encrypted signals provided by the telephone base.

10. The apparatus of claim 9 further comprising a speech decoder coupled to the signal decryptor and for coupling to the utilization device, the speech decoder for generating uncoded speech signals reflecting decrypted signals generated by the signal decryptor, wherein the uncoded speech signals are decrypted signals for use by the utilization device.

11. The apparatus of claim 9 further comprising a demodulator coupled to the signal decryptor and for coupling to the telephone base, the demodulator for generating demodulated signals reflecting signals provided by the telephone base, wherein the decryptor generates decrypted signals which reflect the demodulated signals.

12. The apparatus of claim 9 wherein the signal utilization device comprises a speaker.

13. The apparatus of claim 9 further comprising a utilization device interface coupled to the signal decryptor and for coupling to the utilization device, the interface for adapting the apparatus for operation with the utilization device.

14. The apparatus of claim 1 wherein the signal encryptor comprises a scrambler circuit.

15. An apparatus for providing secure communication of information signals over a communications network, the apparatus for coupling between a telephone base and an information signal utilization device, the telephone base coupled to the communications network and for receiving information signals therefrom, the apparatus comprising a signal decryptor, for coupling to the telephone base and the utilization device, the signal decryptor for generating decrypted signals for use by the utilization device, the decrypted signals reflecting encrypted signals provided by the telephone base.

16. An apparatus for providing secure telephone communication, the apparatus for coupling between a telephone base and a telephone microphone, the telephone base coupled to a communications network, the telephone microphone for generating first signals reflecting speech, the apparatus comprising:

a speech coder for coupling to the telephone microphone, the speech coder for generating coded signals reflecting the first signals; and

a signal encryptor coupled to the speech coder and for coupling to the telephone base, the signal encryptor for generating encrypted signals reflecting the coded signals;

the telephone base for transmitting over the network signals reflecting the encrypted signals.

17. The apparatus of claim 16 wherein the speech coder comprises a CELP coder.

18. The apparatus of claim 16 wherein the signal encryptor conforms to the Federal Information Processing Standard 140-1.

19. The apparatus of claim 16 further comprising a modulator coupled to the signal encryptor and for coupling to the telephone base, the modulator for generating modulated signals reflecting the encrypted signals.

20. The apparatus of claim 19 further comprising a telephone base interface coupled to the modulator and for coupling to the telephone base, the telephone base interface for adapting the apparatus for operation with the telephone base.

21. The apparatus of claim 20 wherein the modulated signals are digital signals and further comprising means, coupled between the telephone base interface and the modulator, for generating analog signals which reflect the digital signals generated by the modulator.

22. The apparatus of claim 16 wherein the telephone microphone comprises a telephone handset microphone.

23. The apparatus of claim 22 further comprising a handset interface coupled to the speech coder and for coupling to the handset microphone, the handset interface for adapting the apparatus for operation with the handset.

24. The apparatus of claim 23 wherein the handset interface provides analog signals and further comprising means, coupled between the handset interface and the speech coder, for generating digital signals which reflect the analog signals provided by the handset interface.

25. The apparatus of claim 16 further comprising a user interface for controlling apparatus operation.

26. The apparatus of claim 25 wherein the user interface comprises a keypad.

27. The apparatus of claim 26 wherein the keypad comprises one or more DTMF signal generators.

28. The apparatus of claim 25 wherein the user interface comprises a display.

29. The apparatus of claim 28 wherein the display comprises a liquid crystal display.

30. The apparatus of claim 25 wherein the user interface comprises means for initiating secure communications.

31. The apparatus of claim 25 wherein the user interface comprises means for initiating clear communications.

32. The apparatus of claim 25 further comprising a control processor coupled to the user interface and the signal encryptor, the control processor for controlling the operation of the signal encryptor in response to signals from the user interface.

33. The apparatus of claim 16 further comprising a removable interface module, coupled to the speech coder and for coupling to the telephone microphone, the removable interface module comprising a microphone interface.

35. The apparatus of claim 16, wherein the telephone base provides second signals reflecting encrypted speech signals received from the communications network, the apparatus for further coupling between the telephone base and a telephone speaker, the apparatus further comprising:

a signal decryptor for coupling to the telephone base, the signal decryptor for generating decrypted signals reflecting the second signals, and

a speech decoder coupled to the signal decryptor and for coupling to the telephone speaker, the speech decoder for generating decoded speech signals reflecting the decrypted signals;

the speaker for generating audible signals reflecting the decoded speech signals.

36. The apparatus of claim 35 further comprising a demodulator coupled to the signal decryptor and for coupling to the telephone base, the demodulator for generating demodulated signals reflecting the second signals.

37. The apparatus of claim 36 further comprising a telephone base interface coupled to the demodulator and for coupling to the telephone base.

38. The apparatus of claim 37 wherein the second signals provided to the telephone base interface are analog signals and further comprising means, coupled between the telephone base interface and the demodulator, for generating digital signals which reflect analog signals provided by the telephone base interface.

39. The apparatus of claim 35 wherein the telephone speaker comprises a telephone handset speaker.

40. The apparatus of claim 39 further comprising a handset interface coupled to the speech decoder and for coupling to the telephone handset speaker.

41. The apparatus of claim 40 wherein the decoded speech signals are digital signals and further comprising means, coupled between the handset interface and the speech decoder, for generating analog signals which reflect the digital signals generated by the speech decoder.

42. The apparatus of claim 35 further comprising a removable interface module, the removable interface module comprising a telephone speaker interface coupled to the speech decoder and for coupling to the telephone speaker.

43. The apparatus of claim 35 further comprising a removable interface module, the removable interface module comprising a telephone base interface coupled to the signal decryptor and for coupling to the telephone base.

34. The apparatus of 16 further comprising a removable interface module, the removable interface module comprising a telephone base interface coupled to the signal encryptor and for coupling to the telephone base.

44. An apparatus for providing secure telephone communication, the apparatus for coupling between a telephone base and a telephone speaker, the telephone base coupled to a communications network and for providing first signals reflecting encrypted signals received from the communications network, the apparatus comprising:

a signal decryptor for coupling to the telephone base, the signal decryptor for generating decrypted signals reflecting the first signals, and

a speech decoder coupled to the signal decryptor and for coupling to the telephone speaker, the speech decoder for generating decoded speech signals reflecting the decrypted signals;

the speaker for generating audible signals reflecting the decoded speech signals.

45. An apparatus for providing secure telephone communication, the apparatus for coupling between a telephone handset and a telephone base, the telephone handset including speaker and a microphone for generating first signals reflecting speech, the telephone base coupled to a communications network and for producing second signals reflecting encrypted speech signals received from the network, the apparatus comprising:

(a) a speech coder for coupling to the handset microphone, the speech coder for generating coded signals reflecting the first signals;

(b) a signal encryptor coupled to the speech coder, the signal encryptor for generating encrypted signals reflecting the coded signals;

(c) a modulator coupled to the signal encryptor and for coupling to the telephone base, the modulator for generating modulated signals reflecting the encrypted signals, the telephone base for transmitting over the network signals reflecting the modulated signals;

(d) a demodulator for coupling to the telephone base, the demodulator for generating demodulated signals reflecting the second signals;

(e) a signal decryptor coupled to the demodulator, the signal decryptor for generating decrypted signals reflecting the demodulated signals; and

(f) a speech decoder coupled to the signal decryptor and for coupling to the telephone speaker, the speech decoder for generating decoded speech signals reflecting the decrypted signals;

the telephone speaker for generating audible signals reflecting the decoded speech signals.

46. The apparatus of claim 45 further comprising:

a user interface for controlling the operation of the apparatus; and

a control processor, coupled to the user interface and the signal encryptor and signal decryptor, the control processor for controlling the operation of the encryptor and decryptor responsive to signals from the user interface.

47. The apparatus of claim 46 wherein the user interface comprises:

means, coupled to the control processor, for initiating secure communications;

means, coupled to the control processor, for initiating clear communications; and

a display, coupled to the control processor, for indicating operation status.

48. The apparatus of claim 45 further comprising a removable interface module, the removable interface module including a telephone base interface and a telephone handset interface,

(i) the telephone base interface for coupling to the telephone base, the modulator, and the demodulator, the telephone base interface for adapting the apparatus for operation with the telephone base,

(ii) the telephone handset interface for coupling to the telephone handset, the speech encoder, and the speech decoder, the telephone handset interface for adapting the apparatus for operation with the telephone handset.