H04K   1/00		̩̿	Secret communication	9230
H04K   1/02		裲οäƽ˾οƤˤ뤿裲οղäˤ	by adding a second signal to make the desired signal unintelligible	2080
H04K   1/04		ȿ֥ˤΡʤȿӰνʬִޤȿžޤӰȿžˤ	by frequency scrambling, i.e. by transposing or inverting parts of the frequency band or by inverting the whole band	1100
H04K   1/06		νǤԼ®٤ޤ𻨤ʽޤϵչԤˤ	by transmitting the information or elements thereof at unnatural speeds or in jumbled order or backwards	705
H04K   1/08		ȤȤѤ뤳Ȥˤ	by varying the polarisation of transmitted waves	57
H04K   1/10		ƱˤޤϽ缡룲Ѥ	by using two signals transmitted simultaneously or successively	2935
H04K   3/00		̿˸й	Jamming of communication; Counter-measures	6880
