Encryption over Repeaters

libuff · Post by **libuff** » Wed Jul 20, 2005 6:23 pm

i am setting up a Conventinal repeater setup with a MTR-2000 with conventional options... i would like to do some encryption over the repeater. what is needed to achieve this... we're using all MTS-2000 radios, and would like to go with native "M" products, would prefer to avoid the aftermarket stuff...

tvsjr · Post by **tvsjr** » Wed Jul 20, 2005 6:32 pm

The native M products are all CVSD, which won't pass through the MTR2000 (audio passband isn't wide enough nor is the response flat enough). You'll need to look into voice inversion as offered by Transcrypt, Midian, and maybe others.

nmfire10 · Post by **nmfire10** » Wed Jul 20, 2005 6:35 pm

Plus securenet has no PL.

libuff · Post by **libuff** » Wed Jul 20, 2005 7:08 pm

thanks guys... was curious what i could do... which repeaters are able to be utilized with DES, or DVP?

tvsjr · Post by **tvsjr** » Wed Jul 20, 2005 7:18 pm

Factory Motorola? Quantar, probably STR3000, whatever the new G-something-or-other repeater is, MSF5000. All have to be configured for Securenet (the base configurations won't support Securenet).

Real crypto requires lots of work for key management, dealing with keyfails, equipped infrastructure and subscriber units, etc. Unless your application requires serious security, the rolling-code voice inversion is much easier to deal with, requires less work, and costs much, much less.

Why are you interested in crypto, out of curiosity?

libuff · Post by **libuff** » Thu Jul 21, 2005 12:49 am

just researching the technology...

RKG · Post by **RKG** » Thu Jul 21, 2005 7:44 am

Stay away from rolling code inversion, though, if you employ (or intend to employ) voting receivers or TRC wireline control.

ASTROMODAT · Post by **ASTROMODAT** » Thu Jul 21, 2005 1:28 pm

If you need to encrypt using current technology radios (as opposed to old legacy stuff), the only sensible approach is a Quantar with the DIU3000, and IMBE, using either DES-OFB or AES-256. Anything else will sound like garbage, and not be very secure at all. You said Motorola, so these would be your best approaches with Moto gear.

Good luck.

tvsjr · Post by **tvsjr** » Thu Jul 21, 2005 2:34 pm

Jesus, Larry, the guy has some MTS2000s and an MTR2000, and you want him to go out and buy Quants, a DIU3000, and XTS5000s?

"Sorry, your Crown Vic won't run 0-60 in 7 seconds. Here, let me sell you a Ferrari."

If he *needs* the security of AES, he's probably a fed and wouldn't be asking those questions here.

More than likely, he's a commercial/industrial user and just doesn't want people eavesdropping, in which case anything equal to or better than rolling-code voice inversion would be more than adequate.

Your rabid fanboyism is really tiring.

Post by **wavetar** » Thu Jul 21, 2005 2:46 pm

Do NOT start this again. Larry is entitled to put his two cents in, just like anyone else. His suggestion is a good one, for anyone with both the need, and the money. Next personal shot gets this thread the lock.

Todd

libuff · Post by **libuff** » Thu Jul 21, 2005 3:17 pm

ASTROMODAT wrote:If you need to encrypt using current technology radios (as opposed to old legacy stuff), the only sensible approach is a Quantar with the DIU3000, and IMBE, using either DES-OFB or AES-256. Anything else will sound like garbage, and not be very secure at all. You said Motorola, so these would be your best approaches with Moto gear.

Good luck.

wow... ok, i apreciate the info, but we're a low budget EMS agnecy... im the radio special projects coordinator... kind of new to the whole world of stuff... thats why we contract out our radio projects... we're setting up a system to be interoperable, however, we would also like some privacy as well... just looking to thwart the casual listener with a programmed radio or scanner... i spoke to trasncrypt and midian, both of which had good products, but, i was looking more toward the factory motorola stuff, such as DES or so... just such that i could have it installed without ribbon cables, or custom solder jobs... we may just develop a simplex encrypted channel that we can use... unfortunately even tho im im one of the richest areas for EMS agencies, i cannot afford XTS radios, or Quantar repeaters, or ASTRO P25 stuff for that matter... we were forced to purchase XTS2500 800 MHz Type II trunked stuff, we took a BIG hit on that stuff... and after doing some shopping around after the purchase, we got a BIG discount on the radios... and our MTS2000's are second hand... thankfully we went new on the infrastructure stuff...

thanks for the info guys...

n9upc · Post by **n9upc** » Thu Jul 21, 2005 4:31 pm

Someone can correct me if I am wrong but will the HTAVS stuff work in an MTS2000 as well as the HT1000 since they are built on the same platform can they not work in the MTS2000.

I have used these on the HT1000 and the encryption works nice and good and if I remember correctly it can pass through a standard reepater.

Be careful if you are using encryption and giving PHI as we were advised that some encryption really can not be used to discuss PHI.

Good luck as we are running into comm problems with our ambulance service also.

ASTROMODAT · Post by **ASTROMODAT** » Thu Jul 21, 2005 7:51 pm

libuff, in clarifying that you only need to thwart casual eavesdroppers, such as scanner listeners, I would agree that you can probably do that with after market 3rd party stuff quite easily. I thought you needed Motorola equipment that was considered secure, which in today's world (if you need to use 100% Motorola) is essentially pointing towards their P25 gear. I believe both Midian and Transcript both could do the job for you, if you are simply concerned about mild type security.

JOHN 1807 · Post by **JOHN 1807** » Fri Jul 22, 2005 9:03 pm

n9upc wrote:Someone can correct me if I am wrong but will the HTAVS stuff work in an MTS2000 as well as the HT1000 since they are built on the same platform can they not work in the MTS2000.

I have used these on the HT1000 and the encryption works nice and good and if I remember correctly it can pass through a standard reepater.

Be careful if you are using encryption and giving PHI as we were advised that some encryption really can not be used to discuss PHI.

Good luck as we are running into comm problems with our ambulance service also.

I would LOVE to know that that is possible, I would like to equipt my mts with an avs board intended for an ht-1000 if that is a possibilty, as the majority of our radios are ht1ks' (and could pass through a non-securenet repeater)