Questions about dual algo modules

[MotoFAN]

Guys!

I have dual algo module (DES-XL / DEF-OFB; not UCM) installed in Astro Saber M3.

Questions:

1. How to find out, what key uses what type of encryption (algo)?
2. How to switch between 2 different algos from radio?

I have KVL and may change anything in CPS.

Beforehand thanks!

[Pj]

Best answers are essentially in here:

http://www.akardam.net/moto/docs/mirror ... yption.pdf
and
http://batboard.batlabs.com/viewtopic.php?t=55693

The radio by default will use -OFB in the digital mode unless you specifically force it to -XL in the codeplug...otherwise it will use the correct algo upon receiving the transmission.

The same key can be used for both. Its been awhile since I have needed to play/load keys in the older astro's but thats what I recall.

[MotoFAN]

Pj,

Thanks! But I am more interesting in analog mode.

Any way to use DES-OFB in analog?

Any way to switch between algos from radio (just by keypress)? E.g. by switching KEYSETS & etc.

[Pj]

No. -OFB is P25 only.

-XL will work in analog and P25

[MotoFAN]

Thanks!

But how about switching? No way other than program different algos in different personalities?

[MotoFAN]

Hi all!

Other question.

What is the right sound for successful keyload? 12 (6x2) short high beeps or one low beep?

KVL says KEY LOAD SUCCESSFUL in both cases.

[MotoFAN]

Other question # 2.

Astro Saber with dual algo module (DVP-XL & DES-OFB, EMC R02.12) and H/W multikey.

How othe same key may be suitable for ASTRO and analog? I have checked many times and 100% sure that first 3 keys works properly for ASTRO and analog (they are loaded by original owner, not me).



As I knew, DVP-XL can't be used for ASTRO. And as Pj said above, DES-OFB can't be used for analog.

Keys in slots 3-10 loaded by me and work only for ASTRO, because "DES only" KVL have been used.

How one key (IA SECURE KEY, ABT SECURE or ABT DLE SECURE) may work for ASTRO and analog?

P.S.

[MattSR]

As I knew, DVP-XL can't be used for ASTRO.

Answer is simple - DVP-XL will work with ASTRO. Its registered in the TIA docs as P25 Algorithm ID 0xA1.

[MotoFAN]

MattSR

Ok, thanks!

I am not an experienced user of Motorola encryption.

[MotoFAN]

I tried DES-XL module (single algo) in ASTRO mode and it does work even when XL Encryption (in Radio Configuration > Secure Configuration > Secure) option disabled! And also when DES-XL Tx Default disabled in Personality. I.e. radio transmits securely in APCO25 and does not say ILLEGAL KEY.

Strange to me... Please help to understand how it's possible if XL is disabled at all.

[Pj]

All the "legacy" encryption will work in ASTRO mode. The module is simply encrypting the existing digital data (the voice after its been thru the digitizing chip) in ASTRO mode.

In analog, the module is converting the voice to a digital format then applying the encryption to that voice so-to-speak - but the encyption is still the same...mixing 1's and 0's to the data

AES, ADP and the such do not encode analog voice and the radios are not setup for that - they are just adding encyption to the digital audio.

Of course its more complicated than that, but thats the jist.

Poor attempt here:

Analog
Voice -> DES module (voice to digital voice) -> DES module (add encyption to digital voice) -> Transmitter -----> Receiver-> DES module (decrypt the data) -> DES module (digital voice to analog) -> audio thru the speaker

Digital
Voice -> Vocoder (speech to digital audio) -> DES module (encypt digital audio) -> Transmitter -----> Receiver -> DES module (decypt the voice) -> Vocoder (digtal voice to analog voice) -> Speaker