Secure transmission over satellite phone network

• US 7,761,095 B2
• Filed: 05/24/2005
• Issued: 07/20/2010
• Est. Priority Date: 03/17/2004
• Status: Expired due to Fees

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Inventors: Reed, Eric, Best, Fiona S., McClintock, Dorothy A., Hartwell, Wesley R., Lee, William Jeremy
• Primary Examiner(s): Gesesse; Tilahun
• Application Number:
  US11/135,397
• Publication Number:
  US 20060270451A1
• Time in Patent Office: 1,883 Days
• Field of Search: 455/12.1, 455/13.1, 455/427, 455/428, 455/429, 455/431, 455/410, 455/411, 455/435.1
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18565 Arrangements for preventing unauthorised access or for providing user protection arrangements for secret or secure communication H04L9/00
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04L 63/0485 Networking architectures for enhanced packet encryption processing, e.g. offloading of IPsec packet processing or efficient security association look-up
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 63/30 for supporting lawful interception, monitoring or retaining of communications or communication related information circuit switched telephony call monitoring H04M3/2281
• CPC Class Codes: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
• CPC Class Codes: H04L 9/3013 involving the discrete logarithm problem, e.g. ElGamal or Diffie-Hellman systems
• CPC Class Codes: H04M 1/2535 adapted for voice communication over an Internet Protocol [IP] network Voice over Internet Protocol (VoIP) network equipment and services H04M7/006; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04M 1/72502 with one base station connected to a single line
• CPC Class Codes: H04M 2250/06 including a wireless LAN interface
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]

Abstract

A reach back secure communications terminal includes a modem to satellite interconnect board that captures DTMF tones, demodulates encrypted modem information, and converts both into an ASCII string for presentation to a data port of a satellite phone, allowing out-of-band control of a non-secure satellite system (e.g., AT command control of a data port) by a user on a secure side of an encryption device, by including the ability to interpret control signals and control the satellite system appropriately. A false dial tone is presented to the encryption device, and the data stream coming from the encryption device is monitored for the presence of dual-tone, multi-frequency (DTMF) tones representing control signals, the DTMF tones are converted to ASCII characters, which are in turn received as control signals by the satellite phone, allowing control of the functions of the satellite system directly from the secure side of the encryption device.

Claims

1. An interface between an encryption device and a satellite phone, comprising:

a modem interface; and

a DTMF to ASCII converter module to receive a digital data stream from said modem interface, to convert a DTMF tone to ASCII by removing in-band control signaling from said digital data stream, and to present said control signaling out-of-band to a data port of said satellite phone.

2. The interface between an encryption device and a satellite phone according to claim 1, wherein:

said modem interface conforms to V.34 standards.

3. The interface between an encryption device and a satellite phone according to claim 1, wherein:

said DTMF to ASCII converter module is formed in a programmable integrated circuit (PIC).

4. The interface between an encryption device and a satellite phone according to claim 1, further comprising:

a FAX/data interface alternatively receiving an output from said modem interface.

5. A method of providing control signals from a user device on a secure end of an encryption device to a non-secure data network, comprising:

receiving an in-band digital data stream;

monitoring said in-band digital data stream for presence of a DTMF tone;

decoding said DTMF tone received in-band from said encryption device;

converting said decoded DTMF tone into ASCII control information; and

presenting said ASCII control information out-of-band to said non-secure data network.

6. The method of providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 5, further comprising:

providing a false dial tone to said encryption device.

7. The method of providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 5, wherein:

said data network is a satellite phone network.

8. The method of providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 5, wherein:

said DTMF tone controls a function of a satellite system directly from a secure side of said encryption device.

9. Apparatus for providing control signals from a user device on a secure end of an encryption device to a non-secure data network, comprising:

means for receiving an in-band digital data stream;

means for monitoring said in-band digital data stream for presence of a DTMF tone;

means for decoding said DTMF tone received in-band from said encryption device;

means for converting said decoded DTMF tone into ASCII control information; and

means for presenting said ASCII control information out-of-band to said non-secure data network.

10. The apparatus for providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 9, further comprising:

means for providing a false dial tone to said encryption device.

11. The apparatus for providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 9, wherein:

said data network is a satellite phone network.

12. The apparatus for providing control signals from a user device on a secure end of an encryption device to a non-secure data network according to claim 9, wherein:

said DTMF tone is used to control a function of a satellite system directly from a secure side of said encryption device.