Radio channels used by local law enforcement and first responders will become encrypted by the end of the year, a Sioux City law enforcement official said Monday.  The change will come as local agencies upgrade radio equipment in order to join Iowa’s statewide radio system by 2017.   Sioux City Police Capt. Marti Reilly on Monday did not specify a date for the change, but he said it has come sooner than expected.  His comments came after the Sioux City Council voted to fast-track the purchase of nearly $2 million in new radio equipment to take advantage of available discounts.  Read more here:  Police: Radio traffic to be encrypted by end of year