DYI Landline Encryption

[Bohrium]

Yes TheFallen, that's exactly how I was thinking it would work.

The reason I was thinking of avoiding the PC's was to avoid any security flaws on them; unless it was a dedicated or non internet machine that is.

[TheFallen]

Yeh, look on ebay, old laptop say 1998 onwards. that'd do the trick, install linux, then all you need are the mic in and line outs.
The only problem then would be sampling the audio. I mean you just need the amplitude every millisecond or so, thats the input data, although how you'd do that in C or another programming language of choice I have no idea.

As I said before, your best bet still remains a Linux box with Miranda IM on it, possibly a https or SSH tunnel on it.