Re: [TSCM-L] {1520} Re: FHSS telephone security

From: coderman <code..._at_gmail.com>
Date: Mon, 7 May 2007 13:35:08 -0700

i would have to argue otherwise, in the sense that the only security
provided is based on the pseudo random hop sequence, which is easily
discerned. (secure against a baby monitor or narrow band scanner,
yes. but i don't think that's the nature of security in question
here.)


> I had a phone ... that used spread spectrum to communicate with the
> base station, while the conversation was in the clear.

almost every FHSS phone system i've seen (excluding military units)
operate this way. hence the "security" is due to channel hopping, and
not any kind of transport privacy via encryption.


> I dont know why
> anyone would engineer a product that way

economics. much, much cheaper to carry an analog voice stream over a
FHSS carrier than to implement good privacy via encryption.

again, i would encourage use of a WPA2 VoIP phone instead of a FHSS
system. this gives you DSSS spectrum usage (possibly OFDM) and an AES
encrypted privacy layer on top to carry the conversation.

best regards,
Received on Sat Mar 02 2024 - 00:57:25 CST