decrypt

I'd like to add ADP decryption capability to OP25. I have been doing research for a while about RC4 cipher (a.k.a. Motorola ADP), so I do know how the cipher works. I have some experience programming in C, so I'd like to know where I should start. It would be great if Boatbod gave me a hand with...

Good day, I've worked with decoding DMR using DSDPlus 1.074 , I have got encrypted output (Enc Group call) and information about it such as (Source, ID, Key and algorithm) . I need software that could decrypt the decoded DMR voice. Thank you

Ok, I live in Garfield County WA. Pomeroy WA. They decided to encrypt all data over radio. 1. Is it illegal for me to decrypt it ? 2. Is it illegal for me to stream decrypted audio ? 3. Is it illegal for me to record decrypted audio and put it on Youtube in WA State ?