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Astro Encryption and clear...

Posted: Thu Aug 15, 2002 5:21 pm
by Josh
What will audio sound like through a transmission of encrypted digital over a radio that doesn't have the encryption key? Will it not come in at all?

-Josh

Posted: Thu Aug 15, 2002 6:32 pm
by XDCLabs.COM
Depends...

1. If the receiving radio is not secure capable. I.e. it does not have encryption turned on in the codeplug, then depending on the version of the host firmware, it will either mute or play the encrypted audio.

2. If the receiving radio is secure capable and it cannot find a key matching the the key id of the key used to encrypt the transmission, then the audio will be muted. Pressing monitor will play the garbled audio.

3. If the receiving radio is secure capable and it finds a key in it's module matching the key id of the key that was used to encrypt the transmission, and the keys are not the same, then the receiving radio will attempt to decrypt the audio (and of course miserable fail without knowing it) and play incorrectly decrypted garbled audio.

The garbled audio sounds like you're talking underwater while taking in water and it is 100% unintelligible. The unofficial Moto term for encrypted or incorrectly decrypted audio is "golly-wobbles".

Posted: Thu Aug 15, 2002 7:12 pm
by Josh
XDCLabs.COM wrote:Depends...

1. If the receiving radio is not secure capable. I.e. it does not have encryption turned on in the codeplug, then depending on the version of the host firmware, it will either mute or play the encrypted audio.

2. If the receiving radio is secure capable and it cannot find a key matching the the key id of the key used to encrypt the transmission, then the audio will be muted. Pressing monitor will play the garbled audio.

3. If the receiving radio is secure capable and it finds a key in it's module matching the key id of the key that was used to encrypt the transmission, and the keys are not the same, then the receiving radio will attempt to decrypt the audio (and of course miserable fail without knowing it) and play incorrectly decrypted garbled audio.

The garbled audio sounds like you're talking underwater while taking in water and it is 100% unintelligible. The unofficial Moto term for encrypted or incorrectly decrypted audio is "golly-wobbles".
Very interesting. O.k., so now I'll know what to look for as far as encyption goes. The radio I will be working with is the XTS3000- it is technically secure capable, however, it won't have any keys on it.

-Josh

Posted: Fri Aug 16, 2002 5:55 am
by Twisted_Pear
From my experience with an XTS and no module installed, if you're scanning a trunked system in conventional mode using the DCSQ mode and you happen upon an encrypted carrier the light (next to ant) will flash twice quickly then pause and flash twice again quickly, and so on, for as long as the carrier is active. Could be the same for a regular conventional channel.

If the radio is trunked I think it won't give any acknowledgement at all.

Posted: Fri Aug 16, 2002 6:41 am
by XDCLabs.COM
For Astro Saber and XTS with host firmware versions 5.x.x and newer, these radios were designed to provide two levels of acknowledgement regarding receiving encrypted signals. If an encrypted voice transmission is detected, the red led is double flashed, compared to singled flashed when there is a regular non-encrypted transmission or plain carrier. This was designed to give any user the indication that someone is talking in encrypted mode. In addition to that, if the radio finds a key matching the key id of the key used to encrypt the voice transmission and unmutes the speaker, then the "circle with a slash" LCD annunciator on the display will flash as well.

Posted: Fri Aug 16, 2002 7:32 am
by Josh
At what dates did firmware 5.x.x come about?

The radio I am going to be getting is one dating from 9-2001

-Josh

Posted: Fri Aug 16, 2002 7:37 am
by XDCLabs.COM
If memory serves me right, that release came out in 1995 or maybe as late as 1996. Usually if a radio is dated a certain year, you should get the current firware for that period.....unlesss.....there is a small chance that someone has cannabalized the radio out of parts.