Digital encryption - is this legit?

[bunny]

YouTube - Nabishi NDB-750 Digital Encryption

i stumbled upon this and wasn't sure how to make it out since i thought aes couldn't be decrypted without billions of years to brute force.

[ersin]

That's right. That's what the video was saying. That analog radio was listening to an old, analog type of scrambling called IIRC frequency inversion. They did that to contrast against the new digital encryption.

See this thread: http://www.radardetector.net/viewtopic.php?t=33751

[Ovencleaner]

unless their is a crypto weakness or "backdoor" discovered, then brute force is the only way.

[ersin]

unless their is a crypto weakness or "backdoor" discovered, then brute force is the only way.

AES has been out for a while now. Both the spec and its rationale. Most likely by now any backdoors should have been discovered. AFAIK, no practical weaknesses have been found. Of course, you can never actually certify an algorithm as "unbreakable". However, if no attacks have been found after a long time then people generally get the idea that the algorithm is strong. It looks like AES is pretty strong; it would require "billions and billions" of years to break using brute force keyspace search. See my posts in that other thread.

[bunny]

then how would one of these chips help decrypt that signal?

[ersin]

then how would one of these chips help decrypt that signal?

These chips have the key. The key is programmed into the chip, either manually with a device or computer, or over the air rekey (OTAR). These are the authorized chips that they were advertising, not any unauthorized thing.

Even if you had the same radio and the same chip as your local PD, you still could not hear their communications unless the chip held the right key.

Does that explanation help?

[bunny]

yes that makes tons of sense!

now do these chips hold the right key for my area? ... oh wait. chp doesn't encrypt anything and its signal is analog anyways, right?

[ersin]

yes that makes tons of sense!

now do these chips hold the right key for my area? ... oh wait. chp doesn't encrypt anything and its signal is analog anyways, right?

The key is changed by the department using the device. How often it's changed depends on how much security they want and how much work they are willing to do. You would need to know someone in your area who has access to the key and is able and willing to re-key the chip for you every time the key is changed.

The signal must be digital for that chip. It doesn't work with analog. Analog is old stuff. I doubt anybody is using analog scrambling today.