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Optical Data Transmission Security System

IP.com Disclosure Number: IPCOM000041823D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Balliet, L: AUTHOR [+2]

Abstract

Security of high data rate data transmission is maintained and monitored through the use of a fiber-optic link and a unique signal-interrupt detection system. As indicated in the drawing, data is transmitted from a first data processing system 10 to a second data processing system 11 by means of an optical transmitter 12, an optical fiber transmission link 13, and an optical receiver 14. This link 13 is an optical fiber cable. Since such cables do not radiate as do wire cables, security cannot be breached by tapping the fiber cable 13 without breaking the fiber or bending it abnormally. In either case, the signal level is interrupted or greatly reduced and such interruption or reduction is detected by a signal interrupt detector 15 to activate an alarm 16.

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Optical Data Transmission Security System

Security of high data rate data transmission is maintained and monitored through the use of a fiber-optic link and a unique signal-interrupt detection system. As indicated in the drawing, data is transmitted from a first data processing system 10 to a second data processing system 11 by means of an optical transmitter 12, an optical fiber transmission link 13, and an optical receiver 14. This link 13 is an optical fiber cable. Since such cables do not radiate as do wire cables, security cannot be breached by tapping the fiber cable 13 without breaking the fiber or bending it abnormally. In either case, the signal level is interrupted or greatly reduced and such interruption or reduction is detected by a signal interrupt detector 15 to activate an alarm 16. Thus, the system operator is immediately apprised of any tampering with the fiber transmission link 13. The signal interrupt detector 15 is designed to operate at a narrower bandwidth and at a lower than normal signal-to-noise level as compared to the normal data path between the optical receiver 14 and the receiving data processing system 11. This improves the sensitivity of the system to fiber link tampering. An enable signal from the data processing system 11 turns on the signal-interrupt detector 15 at the start of a data transmission session and a disable signal turns off the signal-interrupt detector 15 at the conclusion of the data transmission session. This prev...