This video provides examples of encrypted communications and demonstrates the difference in sound between encrypted and unencrypted communications to public listeners .
More police departments look to tune public out (AP):
Police departments around the country are moving to shield their radio communications from the public as cheap, user-friendly technology has made it easy for anyone to use handheld devices to keep tabs on officers responding to crimes.
The practice of encryption has become increasingly common from Florida to New York and west to California, with law enforcement officials saying they want to keep criminals from using officers’ internal chatter to evade them. But journalists and neighborhood watchdogs say open communications ensure that the public receives information as quickly as possible that can be vital to their safety.
D.C. police became one of the latest departments to adopt the practice this fall. Police Chief Cathy Lanier said recently that a group of burglars who police believe were following radio communications on their smartphones pulled off more than a dozen crimes before ultimately being arrested and that drug dealers fled a laundromat after a sergeant used his radio to call in other officers — suggesting that they, too, might have been listening in.
“Whereas listeners used to be tied to stationary scanners, new technology has allowed people — and especially criminals — to listen to police communications on a smartphone from anywhere,” Lanier testified at a D.C. Council committee hearing this month. “When a potential criminal can evade capture and learn, ‘There’s an app for that,’ it’s time to change our practices.”
The transition to encryption has put police departments at odds with the news media, who say their newsgathering is impeded when they can’t use scanners to monitor developing crimes and disasters. Journalists and scanner hobbyists argue that police departments already have the capability to communicate securely and should be able to adjust to the times without reverting to full encryption. And they say alert scanner listeners have even helped police solve crimes.
The Orange County, Fla., sheriff’s office expects to be encrypted within months. Several police departments in the county are already encrypted, and more will follow suit to keep officers safe, said Bryan Rintoul, director of emergency communications for the sheriff’s office.
In California, the Santa Monica police department has been fully encrypted for the past two years, enabling police to communicate more freely during high-risk calls, said spokesman Sgt. Richard Lewis.
Smaller communities like Garden City, Kan. — with a population of roughly 27,000 — are also converting.
“It was an unknown. There was no criminal act, but it concerns the officers when you see the same vehicle keep showing up at your scenes,” said spokesman Sgt. Michael Reagle. “What is their intent when they keep showing up?”
The shift to encryption has occurred as departments replace old-fashioned analog radios with digital equipment that sends the voice signal over the air as a stream of bits and then reconstructs it into high-quality audio. Encrypted communication is generally only heard by listeners with an encryption key. Others might hear silence or garbled talk.
Still, full encryption is cumbersome and difficult to manage, especially for large law enforcement agencies that must keep track of who has the encryption key. The more individuals or neighboring agencies with access, the greater the risk that the secrecy of the system could be compromised and the harder it becomes to ensure that everyone who needs access has it, Blaze said.
“I would not be surprised if a lot of departments that do it would switch back to non-encryption. The practical difficulties of trying to maintain an encrypted system at scale start to become apparent,” he said.