Public Safety Radio Encryption


After the attacks on the World Trade Center and Pentagon, of the problems with the response by public safety agencies was that there was no unified radio system available for responders from the various agencies that responded to use to coordinate their actions.

In New York, NYPD, FDNY, and the Port Authority Police (the WTC is on Port Authority property), operated on three incompatible radio systems with no way for one field unit to talk to another field unit. In Washington, the various agencies that responded to the Pentagon used various radio systems without a common channel or talk group.

In both cases, incident command was fractured and there was no common point of contact.

As a result, in the 15 years later millions upon millions of dollars in federal grants have been awarded to states, regions, counties, and cities to improve “interoperability”. That was a word that if it existed at all, was barely known to anyone in public safety. Now, it’s the key buzzword to getting federal grants. Proposals for communications equipment that don’t feature that word are unlikely to be approved.

Many states opted to build statewide communications systems, usually using trunking technology to provide sufficient capacity for the large number of users. Rhode Island, Louisiana, Tennessee, and several other states have taken this approach. Texas, which is probably to big and geographically diverse for a statewide system, has several regional and county wide radio  systems that are designed to do the same thing.

Some agencies have opted to use some of their money to encrypt all or part of their radio systems. Encryption, as the name implies, makes it impossible for casual listeners to hear the radio transmissions of radio system users. There is technology that might allow reception of encrypted transmissions, but it’s illegal to possess it.

The problem with encryption is that it not only makes it impossible for casual listeners to hear the radio traffic, it can make it impossible for other public safety users on the same radio system to hear neighboring agencies radio traffic. Without the encryption keys programmed during radio set up, the radios of other users are effectively deaf to the encrypted traffic.

The solution would be to share encryption keys among agencies, but surprisingly (to me at least) some agencies refuse to do that. So, if something big happens in their agencies, they will rely upon common channels or talk groups for “interoperability” communications. If, of course, every radio is programmed properly. Which surprisingly often doesn’t happen.

Before I go much further I’d like to preemptively reply to the “HIPAA requires encrypted radio communications so EMS has to have encrypted radios.” comment that is sure to follow.

Here is my reply “Bull shit”.  People who say that are either lying or woefully ignorant about HIPAA or emergency radio communications.

I also recognize that some radio communications should be secure, but for the most part public safety radio communications should be in the clear. When I run into a small public safety agency, usually police, that encrypts all of their radio traffic, the paranoid in me wonders what it is that they are hiding? After all, New York City, Boston, Los Angeles, Chicago, and other big cities don’t encypt most of their radio systems. Washington, DC police do and even there I wonder what the reason . Surprisingly, Philadelphia Fire Department encrypts most of their radio traffic, while the police encrypt only some of their more sensitive channels. Boston Police and EMS use very little encryption, but the fire department makes extensive use of it.

This article,

Emergency agencies begin turning off radio encryption in bid to ‘improve transparency’

mentions some interesting points which critics have brought up in the past.

Some police and fire departments are bucking a trend to conceal dispatch communications from the public, acknowledging that radio encryption has the potential to backfire and put first responders in danger.

Agencies with digital radio systems have turned off the encryption to their main dispatching channels and others have decided not to turn it on. 

They say their officers and firefighters may not be heard during emergencies by responders at neighboring departments with radio systems that either don’t have access to their encrypted channels or aren’t advanced enough to have encryption capability.

Those in favor of encryption cite the following,

… the response to the Boston Marathon bombings in 2013, when people listening to police communications posted misleading and inaccurate information on social media.

Anyone who watched the news during the Boston Marathon bombings, Orlando or San Bernardino attacks, or any other big event knows that most of the misinformation comes from professional news outlets, not social media. Encryption is only going to cause more misinformation to be propagated, not less.

Radio encryption has some applications, but I have to wonder if encrypting all radio communications, especially routine traffic is consistent with the transparency and accountability to the public upon which our system of government is built.



  1. Who cares if “social media” gets inaccurate information?

    The Media got their info from the police, and still got it wrong..

    Breaking news is generally inaccurate.

    • My experience at more than one “big one” type of call has taught me that for the most part the media just makes shit up. It doesn’t matter if they get a full briefing from a PIO or not. Most reporters are hired for their looks, not their brains. The can’t retain information, so they just make it up. Every mass shooting in the past several years has started out with reports of multiple attackers (usually white males) wearing body armor, and armed with “fully automatic semi automatic rifles”. Or some such nonsense. It’s only hours or more likely days later, when more accurate information comes out.

      Frankly, people listening on scanners and posting on social media are probably as or more likely to have correct information than so called “journalists”.

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