Decode ARC4 encryption (WITH KEY DATA) with SDR

[knockoffham]

I'm president of the amateur radio club at my university. I am working on a project that might turn into another member's research project if I can do this.
1. Are there any SDRs and associated programs (preferably open source) that can decode conventional P25 that's encrypted with ARC4/ADP? They key would be known and passed to the SDR/program. I am not a noob asking to decode encrypted traffic without a key. This is in a controlled environment.
2. Or, are there any programs I can use to generate and/or decode a complete P25 bitstream without using any RF at all? Preferably one program/computer to generate the bitstream, into a file, and another program to attempt to decode it. Would be cool if we could encode/decode voice but not necessary. If no such thing exists, we will probably use a P25 radio at low power into a dummy load going directly into an SDR or perhaps some intense attenuation and then through a coax cable. Thanks

 

[boatbod]

OP25 can do known-key P25 with RC4, DES and AES.

 

[Forts]

DSD-FME/DSD-NEO as well.

 

[lwvmobile]

You might also find one of my side projects, crypthings, to be of interest. Its basically just a bunch of simple tools for keystream generation and application, along with a write up and examples from FIPS and NIST resources.

 

[knockoffham]

Great. Those all sound like the exact sorts of things I am looking for. I will do my research on those. Thanks so much!!!

 

[WV8VFD]

You might also take a look at DVM Project as well. You could set up an FNE and DVM Console. If you connect the console to the FNE you can generate P25 with no RF. If you turn debugging on you will get full hex dumps of the P25 frames. If you throw in an MMDVM hotspot and a Pi (or USB board) you could generate a P25 signal with minimal (10mW I believe) RF and then decode it with an SDR. IIRC dvmconsole supports ADP, DES, and AES.

 

[knockoffham]

You might also take a look at DVM Project as well. You could set up an FNE and DVM Console. If you connect the console to the FNE you can generate P25 with no RF. If you turn debugging on you will get full hex dumps of the P25 frames. If you throw in an MMDVM hotspot and a Pi (or USB board) you could generate a P25 signal with minimal (10mW I believe) RF and then decode it with an SDR. IIRC dvmconsole supports ADP, DES, and AES.

Great. Was considering playing with MMDVM anyway