Basic encryption is included with all Kenwood NexEdge radios. Turning it on is just a simple setting in the programming software. Since the signal is digital, it doesn't deteriorate the signal.
If the agencies you want to listen to are running NexEdge conventional, you can monitor them with a Kenwood Nexedge radio. If they are UHF or VHF, they can be monitored with an Icom IDAS radio if they are running in 6.25KHz mode. Kenwoods do 12.5KHz NXDN, however the Icom's will not.
If they are running Kenwood trunking, you will only be able to monitor them if you have a Kenwood radio that has been programmed with the correct programming key. You cannot monitor a Kenwood NexEdge trunking system by using a NexEdge radio in conventional mode and sitting on one of the frequencies. This may work with other trunking system, but it will NOT work with the Kenwood NexEdge trunking protocol.
Icom and Kenwood trunking are NOT compatible, either.
Maybe some day the scanner manufacturers will catch up with this.