At 3/4/2009 09:49, you wrote: >I have to agree with Eric on this one. I have set up the DPL on the output >of the repeater different than the input so it s harder to find the DPL >code. Motorola is great about this for programming as it s a lot harder to >hack the repeater if you have two different DPL codes for in and out. Most >handhelds that you can modify don t do thins and commercial radios can do >it with very little programming. > >Peter Summerhawk > > -----Original Message----- >From: [email protected] >[mailto:[email protected]] On Behalf Of Eric Lemmon > >Jason, > >The upside to using DPL (CDCSS) for repeater access is that few, if any, >wannabe users will be able to get in- IF you encode a different code (DPL or >PL) than you decode. If your repeater passes through the incoming code to >the output, you have already given the hackers the clues that they need.
The above might lead some to believe that DPL is relatively secure. Remember that there are only ~104 valid DPL codes. There are 32 or 37 standard PL tones - let's say about about a third of the number of valid DPL codes. We agree that PL freq. of a repeater is fairly easy to determine, even if it doesn't pass PL. There are ~3 times as many DPL codes, so figuring out a DPL code is 3 times harder than "relatively easy". For the few times I really had a nasty idiot problem on my system, I used DTMF access. Bob NO6B
