Communications security

L1 mm COMMUNICATIONS The problem of unauthor- ized access to information in transit is as old as mankind itself. Each ad- vance in the means of transferring information has tended to be ac- companied by more soph- isticated possibilities for compromising that infor- mation. Thus, in 1986, despite the millions of possible frequency hopping sequences it may possess, the integrity of a modern military radio which falls into enemy hands is assumed to be no more than a few hours. However, there has been a fundamental change in one aspect of this sector in recent years. Tradition- ally, interest in secure communications was con- fined to the military and diplomatic communities. Today, because of the in- creased dependence on the continual exchange of information-be it techni- cal, financial, or per- sonal-the problem ap- plies equally to industry, commerce, and public administration. Consequently, an industry dedicated to interfering with communication ter- minals of all sorts has ...