> In the case of D-STAR, the algorithm is well known, it's just not analog FM For a long time the audio codec was only available in a chip (technically a reado

> In the case of D-STAR, the algorithm is well known, it's just not analog FM For a long time the audio codec was only available in a chip (technically a readout protected microcontroller). There are patents on the audio codec, but they didn't disclose enough of it to decode it, only enough to make it unlawful for other people to publish compatible implementations (which, of course, kept the resources available for reverse engineering low). For a while I contemplated selling bespoke custom versions of Opus as a bit of performance art under licensing where the first copy cost $500 and all further copies cost $1,000,000 with some marketing copy about keeping lids off your repeaters. ... just to see how the FCC would react. Considering that they let AMBE use get away with it, as the old joke goes: We've already established what kind of licensing regime they'll permit-- pay to access encrypted audio-- my performance art differed only by the price. :) > The reason amateur radio exists is because we follow the rules. It can all disappear overnight if you violate them. There are a few well-known bad apples that make it harder for all of us. It's not to be encouraged. Personally, particularly on bands above 70cm, I think the prohibition against encryption is killing amateur radio. The lack of encryption for signals that would be naturally point to point anyway and disturb no one inhibits a lot community use, and the relative non-usage of these allocations risks use losing them. I'd much rather see a rule that allowed encryption on 33cm+ subject to the constraint that stations have to be identified, non-profit in nature, cooperate with local coordination, and act as secondary users to non-encrypted uses.