wn9nbt@ecn-ee.UUCP (08/24/84)
#N:ecn-ee:14900008:000:729 ecn-ee!wn9nbt Aug 23 23:54:00 1984 Thanks to all of the replies from my question about the White House Security Radios that are not "receivable" with a conventional scanner. Most replies suggest that they are using a Motorola system that employs the DES algorythm or a similar method developed by Motorola. I built a simple circuit years ago to listen to a local Police department that used a speech inversion scheme. That turned out to be quite simple to defeat. This appears to be quite secure and for all practical purposes, extremely difficult to impossible to decode, without the key /etc. Sorry I didn't thank everyone personally, but I don't have access to arpanet, where several of the replies came from. Thanks !!......Dave Chasey -- wn9nbt