DSD-FME not showing encryption details and AMBE frames

[dolman]

Might be a silly question, but I’m monitoring a few DMR frequencies in my area. They’re all encrypted, so I can’t decode the voice, but I’m trying to gather as much info about them as possible. I’m using DSD-FME with the -Z option to figure out encryption algorithm, it shows it just fine:

Slot 1 DMR PI H- ALG ID: 0x21 KEY ID: 0x03 MI: 0x1BA6129B[0m
[36m DMR PDU Payload [21][10][03][1B][A6][1D][B9][00][00][03][5C][2D][0m
13:05:24 Sync: +DMR   slot1  [slot2] | Color Code=01 | IDLE
[33m Activity Update TS1: Group Voice; Hash: 9; TS2: Idle; Hash: 0;
 SLCO Completed Block [18][00][90][0A][00]
[0m
13:05:24 Sync: +DMR  [SLOT1]  slot2  | Color Code=01 | VC1*
 AMBE 0BD6F009CF1780 err = [0] [0]
 AMBE BC83A6FAD55500 err = [0] [0]
 AMBE F480F302AB4080 err = [0] [0]

However, there are a few frequencies with pretty strong signal where I don’t see encryption details or AMBE frames in the log:

22:05:31 Sync: +DMR   slot1  [slot2] | Color Code=11 | TLC [31m
 SLOT 2 TGT=200 SRC=59028 FLCO=0x00 FID=0x10 SVC=0x40 Group [31mEncrypted Call [0m
[36m DMR PDU Payload [00][10][40][00][00][C8][00][E6][94][1E][AA][8E][0m
22:05:31 Sync: +DMR  [slot1]  slot2  | Color Code=11 | IDLE
22:05:31 Sync: +DMR   slot1  [slot2] | Color Code=11 | TLC [31m
 SLOT 2 TGT=200 SRC=59028 FLCO=0x00 FID=0x10 SVC=0x40 Group [31mEncrypted Call [0m
[36m DMR PDU Payload [00][10][40][00][00][C8][00][E6][94][1E][AA][8E][0m
22:05:31 Sync: +DMR  [slot1]  slot2  | Color Code=11 | IDLE
[33m Activity Update TS1: Idle; Hash: 0; TS2: Group Voice; Hash: 118;
 SLCO Completed Block [10][80][07][60][20]

Any idea why DSD-FME wouldn’t show this information on those frequencies?

 

[lwvmobile]

My Spider Senses are tingling.

Create a sample of the latter and I'll examine it. -c dmr_capture.bin, capture some traffic that fits the description you give, compress it as a zip file and attach it.

 

[dolman]

I’ve sent you a private message with the captured samples.

 

[dolman]

Mystery solved – DSD-FME doesn’t show the PI header or Encryption Identifiers because those transmissions are secured with simple Motorola BP keys. Thread may be closed.