RIC 0004520 Encrypted Messages

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MW0MWZ
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RIC 0004520 Encrypted Messages

Post by MW0MWZ » Mon May 13, 2019 4:28 pm

I spoke to the one of the DAPNET team about this RIC since the UK is not allowed to use encryption for HAM use, and I was concerned about the encrypted looking messages;

It turns out that RIC 0004520 is a special system RIC that is used for Skyper pagers, these devices need some special data format, its not encrypted, it just looks weird because the character set has to be rotated by 1 character for the Skyper pagers to understand it, so we need to rotate by -1 char.

In order for us humans to read the text, I made a modification to the dashboard to automatically clear the ROT-1 text for that RIC, for added fun I also took a stab at the symbol set that is ALSO being rotated (this is un-usual, normally ROT is only used on text) and that seems to work, but probably needs more testing.

So from the next time you all update, you should now be able to read the (not so exciting) messages going to RIC 0004520.
Andy

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Re: RIC 0004520 Encrypted Messages

Post by MW0MWZ » Mon May 13, 2019 8:31 pm

Dashboard code for translate Skyper messages has been improved (thanks to a superb tip from Kim - DG9VH), rather than my substitution guess, the dash now rotates the characters by -1 properly, Kim also helped me understand the RIC/SLOT values for Skyper too, those are now also displayed along with the message content.
Andy

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Re: RIC 0004520 Encrypted Messages

Post by G4GBA » Thu May 23, 2019 7:30 am

Great job on 'decrypting' Skyper - almost a Caesar substitution cipher :)

I do notice that a connected Nextion display is not displaying it correctly (as it does on the Dashboard) and not 'decrypting' - Would it be possible to add this to a future release? Hope I've asked a valid question and it's not something else I've done ....

Many thanks for all your work on this and everything else!

Cheers
Charles G4GBA

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Re: RIC 0004520 Encrypted Messages

Post by MW0MWZ » Tue Jun 04, 2019 2:32 pm

G4GBA wrote:
Thu May 23, 2019 7:30 am
Great job on 'decrypting' Skyper - almost a Caesar substitution cipher :)

I do notice that a connected Nextion display is not displaying it correctly (as it does on the Dashboard) and not 'decrypting' - Would it be possible to add this to a future release? Hope I've asked a valid question and it's not something else I've done ....

Many thanks for all your work on this and everything else!

Cheers
Charles G4GBA
Almost a Caesar, yes - that is typically ROT-13, so that you can encode/decode the same way, in this case its ROT +1 and then ROT -1 :)
Ahh the Nextion, well yes and no, so the problem with the nextion is that I would have to add these to MMDVMHost to take care of it, not really a problem but that means we assume that everyone only uses DAPNet and uses the same IDs for Skyper pagers - I dont mind making that assumption on the dash since its part of Pi-Star and we maintain it, but modifying MMDVMHost for the world - thats another thing.

Making pulls like that for the up-stream I have to be mindful of both Pi-Star and the rest of the world, so lets call it a maybe.
Andy

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