Default ENC on Phase I systems Question

[mmtstc]

On my states Phase I system (MN's ARMER), like many other phase I systems, has talkgroups that either do not allow ENC, have selectable ENC or else have ENC enabled by default.

On the talkgroups are defaulted to be encrypted, i have seen a couple fire departments with a talkgroup that is set to that which is used by our states Bureau of Criminal Apprehension. My question being, since this department is using XTS 2500 portables and don't have the ability to toggle their encryption on or off for ANY talkgroup, is the radio doing the encryption or is the radio system doing the encryption?

I know 2500's can do ADP, but most everything on our radio system is DES if I recall correctly.

The point of this question is, if the system is doing the encryption, then in theory, could you perhaps intercept these transmissions when they are coming from the sending radio since they wouldn't be ENC at that point as they have not yet hit the radio system? Additionally, if I was using my XTS5000 on the same talkgroup, but I had my ENC toggle set on, would my outbound transmission be ENC or would if my in the clear and just allowing the system to take care of business?

I understand that there is no reasonable way of decrypting communications, nor do I have any interest in it, this is more of a general thought i had running through my head.

 

[xts3000r]

no. if the radio thats talking dos not have the enc. and key in it. it wont tx on the system. the system wont give it a talk path. and the system dos not take a non enc transmission and make it a enc transmission. it would not work. and so if the xts2500 are tx on the enc talkgrups. then they have enc in them. and a xts2500 can do aes256 des-lxofb and adp

 

[SCPD]

The enc can be selected on/off on XTS2500 via menu on the screen. The talkgroups can be slaved to secure or clear in the radio and to ignore the enc setting. So the user does not have to turn the encryption on/off,

 

[wlmr]

In case the above posts aren't clear to you, the short answer is the radio does the encryption. By the time it hits the radio's antenna it's no longer clear.

 

[mmtstc]

thanks for clearing this up for me everyone.

Although this is off topic and probably more appropriate for the motorola forum, have the 2500's always been able to do the encryption or is that a newer feature (like within the past 4 years new)? I fail to understand why an agency would choose the 5k's over the 2500's...

Can an XTS2500 be programmed to toggle ENC other ways than through a menu, perhaps through the 3 position selector by removing the Scan List Edit function or perhaps one of the side buttons, like you could do with Waris CPS?

 

[gary123]

Yes an XTS can be set up to mechanically switch between ENC and non ENC. Our radios are set up that way.

thanks for clearing this up for me everyone.

Although this is off topic and probably more appropriate for the motorola forum, have the 2500's always been able to do the encryption or is that a newer feature (like within the past 4 years new)? I fail to understand why an agency would choose the 5k's over the 2500's...

Can an XTS2500 be programmed to toggle ENC other ways than through a menu, perhaps through the 3 position selector by removing the Scan List Edit function or perhaps one of the side buttons, like you could do with Waris CPS?

 

[jim202]

Encryption is a software / firmware part of the radio itself. Those channels that use full time encryption are set in the software programming by a per channel setting by the person programming the radio. Those channels that can have the operator turn it on and off use a switch on the radio that again was set up that way in the radio software programming.

An interesting point of encryption is that the radio is set up to receive either a clear signal or an encryption signal automatically. If the channel is programmed operator selectable, the operator doesn't have to do anything on the receive end. The radio will do it all.

Some radio trunking systems have the ability to reprogram a radio over the air without the user doing anything. This cuts down on the time a radio tech needs to put his hands on the radio to do any software changes to it. The down side is that it takes a finite amount of time to do the programming changes. If there are a number of radios needing changes, it will take some time for all of them to get done. Best to do this over night. You need to leave your radio turned on over night for the changes to take place if that is when the system manager does the changes. During the day, normal system traffic slows down the process.

It hasn't been asked or mentioned on this thread, but the main difference between the XTS2500 and the XTL5000 portable when it comes to encryption, is the 5000 can handle multiple encryption keys.

 

[K8TEK]

XTS2500s most certainly can do DES-OFB and AES256.

 

[SCPD]

XTS2500s most certainly can do DES-OFB and AES256.

Not at once

 

[ThinBlueLine22]

thanks for clearing this up for me everyone.

Although this is off topic and probably more appropriate for the motorola forum, have the 2500's always been able to do the encryption or is that a newer feature (like within the past 4 years new)? I fail to understand why an agency would choose the 5k's over the 2500's...

Can an XTS2500 be programmed to toggle ENC other ways than through a menu, perhaps through the 3 position selector by removing the Scan List Edit function or perhaps one of the side buttons, like you could do with Waris CPS?

The answer to your first question is..."Slick Salesmen". Our vendor never tried to push 5000. I'm not sure what the differences between the 2500 and 5000 really are, but there is nothing I need that the 2500 can't do.

Second question...Yes, the concentric switch on the top can be used to toggle encryption on an off. Our vendor did not recommend doing this because it would be too easy to accidentally move that switch. All of our encrypted channels will be "strapped" (automatic encrypt when on a designated t/g). But only radios that have the encryption will have those t/g in them.