扰频

zuì xīn de jī qì duì xìn hào zuò rǎo pín chǔ lǐ tōng huà jiù bù yì bèi zhēn tīng le

最新的机器对信号作扰频处理，通话就不易被侦听了。

The latest machines scramble the messages so that the conversation cannot easily be intercepted.