H04K   1/00  \	0	0	5J104	H04K   1/00	300	̩̿	Secret communication (ciphering or deciphering apparatus <u>per se</u>; systems with reduced bandwidth or suppressed carrier H04B 1/66; spread spectrum techniques&nbsp;H04B 1/69; by using a sub-carrier H04B 14/08; by multiplexing H04J; transmission systems for secret digital information H04L 9/00; secret or subscription television systems H04N 7/16, H04N 21/00)
H04K   1/00  A	0	0	5J104	H04K   1/00	110	ȿѲ	changing the carrier frequency
H04K   1/00  Z	0	0	5J104	H04K   1/00	1009	¾ΤΡ㡥֥̿	Others, e.g. scramble communication
H04K   1/02  \	1	1	5J104	H04K   1/02	414	裲οäƽ˾οƤˤ뤿裲οղäˤ	by adding a second signal to make the desired signal unintelligible
H04K   1/04  \	1	1	5J104	H04K   1/04	479	ȿ֥ˤΡʤȿӰνʬִޤȿžޤӰȿžˤ	by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band
H04K   1/06  \	1	1	5J104	H04K   1/06	352	νǤԼ®٤ޤ𻨤ʽޤϵչԤˤ	by transmitting the information or elements thereof at unnatural speeds or in jumbled order or backwards
H04K   1/08  \	1	1	5J104	H04K   1/08	9	ȤȤѤ뤳Ȥˤ	by varying the polarisation of transmitted waves
H04K   1/10  \	1	1	5J104	H04K   1/10	37	ƱˤޤϽ缡룲Ѥ	by using two signals transmitted simultaneously or successively
H04K   3/00  \	0	0	5J104	H04K   3/00	236	̿˸й	Jamming of communication; Counter-measures (counter-measures used in radar or analogous systems G01S 7/00)
