Decoding Encryption with Permission...

[rescue161]

I was sitting here reading a post about how illegal it is to decode encryption. I laugh at the posts about how DES can be cracked with very little effort and how unsecure it is.

My question is, what if I gave folks permission to decode my transmissions? You know, make it into a contest so to speak. I could even make a recording of of it and post it somewhere for easy access. It'd probably go something like this:

I would record a 10 second message and post it somewhere. I would imagine that the sooner it was decoded, the better the prize would be. So if it's decoded within 24 hours, the prize would be a used Pro-96 and if it's decoded within a week, the winner will receive the radio that I used to make the transmission (438-470 MHz Systems Saber with charger - Sorry, no KVL). The winner would have to send me an email or PM with the text of the message AND tell me what they used to crack my DES code.

Now this is not a "go" as of yet. I'm just checking the waters to see if this is even legal. I don't how it would be if it's my transmission, so we'll see.

Anyone up to the challenge?

Am I crazy?

 

[N_Jay]

I was sitting here reading a post about how illegal it is to decode encryption. I laugh at the posts about how DES can be cracked with very little effort and how unsecure it is.

My question is, what if I gave folks permission to decode my transmissions? You know, make it into a contest so to speak. I could even make a recording of of it and post it somewhere for easy access. It'd probably go something like this:

I would record a 10 second message and post it somewhere. I would imagine that the sooner it was decoded, the better the prize would be. So if it's decoded within 24 hours, the prize would be a used Pro-96 and if it's decoded within a week, the winner will receive the radio that I used to make the transmission (438-470 MHz Systems Saber with charger - Sorry, no KVL). The winner would have to send me an email or PM with the text of the message AND tell me what they used to crack my DES code.

Now this is not a "go" as of yet. I'm just checking the waters to see if this is even legal. I don't how it would be if it's my transmission, so we'll see.

Anyone up to the challenge?

Am I crazy?

'

Yes it is legal (layman's interpretation, not be confused with a lawyers determination), and your radios are safe as long as no one guesses your key. (So don't use all zeros)

 

[DaveNF2G]

There is no poll option for anyone who thinks it would take more than a week.

 

[rescue161]

You know I thought of that after I hit the submit button. The main purpose of this pole is to prove to everyone that the DES that was cracked was NOT in an RF invironment and that DES over radio waves is more secure than DES protecting a text document.

It would also prove to me that I'm wrong if someone can decode my message in less than a week. If they don't succeed within the week period, then they don't get a prize, so I left it out.

If a moderator can add that in, it would be good.

 

[iMONITOR]

Can an encrypted transmission (other than audio inversion) be decrypted after the fact, as a saved audio file, or does it have to be done in real time at the RF level? I have no idea, that's why I'm asking.

 

[N_Jay]

Can an encrypted transmission (other than audio inversion) be decrypted after the fact, as a saved audio file, or does it have to be done in real time at the RF level? I have no idea, that's why I'm asking.

If the "audio" file contains enough information to get the bit stream.
That would depend on the type of modulation, the type of detection, and the type of recording.

It does not need to be real time as the transmission is one way and the receiving unit has no way to know when the transmission was actually first generated.

 

[mancow]

Would it be CVSD Securenet or P25 CAI?

 

[N_Jay]

Would it be CVSD Securenet or P25 CAI?

or Astro, or AEGIS, or Provice, or . . . .? :twisted: :lol: :twisted:

 

[rescue161]

Plain old DES - No P25. I can create a P25 DES-XL or a DES-OFB file too, but figured plain old DES would be better due to the fact that a lot of people think that DES is not secure.

 

[N_Jay]

Plain old DES - No P25. I can create a P25 DES-XL or a DES-OFB file too, but figured plain old DES would be better due to the fact that a lot of people think that DES is not secure.

I think that was FSK, so as long as it is not filtered too much and you have a good edge detector circuit (or software) you should be able to recover the data from a audio file.

 

[JnglMassiv]

I'm a bit of a Motorola Securenet student and read all that I can about the assorted /\/\ crypto schemes and implementation. I have a fair collection of gear too. I've never heard anyone (reliable) even claim that they or someone they knew had decrypted even the weakest Securenet messages. We can all agree it's possible but I've never heard evidence that its been done on a hobbiest level.

 

[rescue161]

I'm a bit of a Motorola Securenet student and read all that I can about the assorted /\/\ crypto schemes and implementation. I have a fair collection of gear too. I've never heard anyone (reliable) even claim that they or someone they knew had decrypted even the weakest Securenet messages. We can all agree it's possible but I've never heard evidence that its been done on a hobbiest level.

Same here, but 100% of the ones that have voted tend to believe that it's possible in less than 24 hours.

Okay guys, I'm gonna make it as easy as possible as far as the recording goes. I'm going to post two recordings - One using a discriminator tap plugged into a sound card and one just using the headphone jack into the sound card. I'll try to remove the squelch from the beginning and ends on the disc tap recording.

As soon as the audio files are posted, the timer will start. Remember though, just giving me the message is not good enough. I need how you did it and what you used to decode it. Sound fair?

 

[rescue161]

Also, what good would finding out what the message is without being able to decode future transmissions, so I will also need the key string.

Now that sounds fair.

I will also post the rules again BEFORE I submit the audio files so there are no problems when / if a winner emerges.

 

[N_Jay]

Same here, but 100% of the ones that have voted tend to believe that it's possible in less than 24 hours.

Okay guys, I'm gonna make it as easy as possible as far as the recording goes. I'm going to post two recordings - One using a discriminator tap plugged into a sound card and one just using the headphone jack into the sound card. I'll try to remove the squelch from the beginning and ends on the disc tap recording.

As soon as the audio files are posted, the timer will start. Remember though, just giving me the message is not good enough. I need how you did it and what you used to decode it. Sound fair?

Oh come on, just the message should be all required to prove decryption (unless you either make the message too easy to guess or you are foolish enough not to keep it 100% secret).

Don't worry, your radios are safe.

EDIT: Also assuming you don't use an easy to guess key.

 

[rescue161]

Okay, okay.

You do not have to provide the key along with it.

 

[N_Jay]

Okay, okay.

You do not have to provide the key along with it.

You could ask for the decoded audio.

Heck, I would love to hear when people come up with.
(Not that I think anyone is going to get anywhere with it)

 

[rescue161]

Me too.

The whole reason behind this is that people tend to think that since a text file using DES was cracked that it is easily cracked over the airwaves.

There is a HUGE difference in text documents versus audio.

I'm still trying to get the audio files recorded. Should be any minute now.

 

[scannerfreak]

Not to mention what it took to crack the text file..

PS- We are not able to edit polls or I would have for ya

 

[rescue161]

No worries on the poll edit...

I KNOW it's gonna take longer than a week.

Whoever can prove me wrong gets the prize. More to follow once I get the files recorded.

 

[N_Jay]

Me too.

The whole reason behind this is that people tend to think that since a text file using DES was cracked that it is easily cracked over the airwaves.

There is a HUGE difference in text documents versus audio.

I agree and have stated so, but the usual suspects always start an argument about it.

Lest see how they do with the challenge.