XPR 7550 firmware

[alcahuete]

Fair enough. TBH Enhanced privacy will do the job but if ya want AES then AES it is

Enhanced Privacy also sounds terrible in comparison to AES.

 

[kayn1n32008]

Enhanced Privacy also sounds terrible in comparison to AES.

They sound no different. EP/AES sound worse than BP/clear because encryption was an after thought. The protocol steals voice payload bits for the KID, algorithm and initialization vector.

 

[alcahuete]

They sound no different.

They absolutely do. Motorola themselves admitted at one point that there is a loss in audio quality (though slight) with Enhanced Encryption. In my experience, it's enough loss in quality to be noticeable.

 

[K2NEC]

Ok I think we are hijacking this thread at this point

 

[kayn1n32008]

They absolutely do. Motorola themselves admitted at one point that there is a loss in audio quality (though slight) with Enhanced Encryption. In my experience, it's enough loss in quality to be noticeable.

On DMR EP and AES both suffer from audio quality loss. There is a noticeable loss in audio quality between clear and AES encrypted DMR. That loss of quality is the same when using RC4 or AES256 on DMR. Have you even used AES on DMR?

 

[kayn1n32008]

Ok I think we are hijacking this thread at this point

I agree. Maybe the mods can separate the encryption posts into a separate thread.

 

[alcahuete]

On DMR EP and AES both suffer from audio quality loss. There is a noticeable loss in audio quality between clear and AES encrypted DMR. That loss of quality is the same when using RC4 or AES256 on DMR. Have you even used AES on DMR?

Vs. no encryption, yes, of course there is a difference. However, there is also a difference between 40-bit and AES256. Here is straight from the Trbo system design manual:

Enhanced Privacy uses multiple keys and a random number to ensure that the encryption data is different for each data message and each superframe of a voice message. This requires transporting crypto parameters (e.g. key Identifier, Initialization Vector) with the voice or data payload. A voice message, in the case of Enhanced Privacy, requires an additional header and replaces some of the least important bits of the voice payload with the Initialization Vector. The additional header increases the System Access Time except when Talk Permit Tone is enabled (in repeater mode) where the additional header replaces one of the normal voice headers. The replacement of payload bits reduces the voice quality. Note that the reduction in voice quality is barely noticeable.

If you understand how that encryption works, the initialization vector actually uses less voice data the larger the key. 128-bit sounds better than their 40-bit, 256-bit sounds better than both. Is it noticeable? To my ears it certainly is, and certainly on the fringes of coverage, where important voice and data bit are being used for other things.

Have you even used AES on DMR?

How do you think I'm making my comparison? I have several Motos and several more Anytone's (though those don't have 40-bit, for comparison).

 

[K2NEC]

As long as we are disputing this, enhanced privacy is better than no privacy. AES is better than enhanced privacy. No discussion there. However for 99.999% of people, enhanced privacy is more than enough to stop most people from listening to their transmissions. Does that mean it's foolproof? Absolutely not. Does that mean that someone can't listen if they REALLY wanted to? Absolutely not. But if someone want's to stop the average listener from being able to hear transmissions, EP is MORE than enough. If you are using AES, you either really have something to hide or are very determined not to have anyone listen to your transmissions, at that point it also becomes suspicious about what you are doing. (Of course this depends on the application and scenario. As with everything, YMMV)

 

[Floridarailfanning]

On DMR EP and AES both suffer from audio quality loss. There is a noticeable loss in audio quality between clear and AES encrypted DMR. That loss of quality is the same when using RC4 or AES256 on DMR. Have you even used AES on DMR?

I run EP on all of my radios and have NEVER noticed any audio difference compared to clear DMR. I'm not saying that voice bits aren't diverted for RC4 but it's not noticeable on simplex or repeated.

As long as we are disputing this, enhanced privacy is better than no privacy. AES is better than enhanced privacy. No discussion there. However for 99.999% of people, enhanced privacy is more than enough to stop most people from listening to their transmissions. Does that mean it's foolproof? Absolutely not. Does that mean that someone can't listen if they REALLY wanted to? Absolutely not. But if someone want's to stop the average listener from being able to hear transmissions, EP is MORE than enough. If you are using AES, you either really have something to hide or are very determined not to have anyone listen to your transmissions, at that point it also becomes suspicious about what you are doing. (Of course this depends on the application and scenario. As with everything, YMMV)

Agreed. If you MUST have AES you probably shouldn't be using TRBO.

 

[N4KVE]

I think it’s more “Since Moto doesn’t want us to have AES on Trbo radios, we must have it”.