Researchers Find ‘Backdoor’ in TETRA Encrypted Police and Military Radios

[JvdK]

For those who have high hopes for decrypting TETRA:

this breach in the encryption of TETRA TEA1 was discovered by 2 dutch IT technicians over 1 year ago. Instead of spreading their discovery in the open, they informed the security services about this backdoor and kept it quiet. During this year users of TEA1 could install the necessary updates to their system and close this backdoor.

For those who can read a newspaper article in Dutch (or can use Google translate):

Welcome to nginx

explanation by Midnight Blue (in English):

TETRA:BURST | Midnight Blue

Midnight Blue will reveil all technical details at Black Hat USA (Las Vegas) on August 9th, 2023

 

[radionx]

"Well, you're wrong. A couple of systems is far from "taking off", technically or anecdotally."

MPT1327 is more widespread than Tetra in the US if i'm not mistaken.

Better keep it that way.

 

[adsbgreenock]

Hi there , Its funny how these "backdoors" or exploits are always revealed whenever the authorities have leveled up and moved on to another part of the spectrum , dont you guys think?

Just as the ESN or Emergency Services Network is about to be rolled out by phone network provider EE, here in the UK as an example

I think its the usual story though, when the military , police and other blue light authorities are finished playing with a certain mode or part of the spectrum , it usually opens things up for joe public to use or access.

Regards

 

[steve9570]

There is a large story on this in this months WIRED magazine. can be seen on line also Wired.com

 

[batdude]

If anyone is interested, here‘s that paper on DVP (non-XL):

https://www.cryptomuseum.com/crypto/motorola/saber/files/vulcan_201409.pdf

hey, i got a shout out as a provider of sparse and/or inaccurate info in that paper

it was 1995. info on Securenet stuff was really hard to find at the time... Reference 7 ... LOL and most everyone was still on 28.8k dialup. most of the info for my article was from the various books / manuals at the local Moto shop....

Encryption Protocols

 

[ff2sherman]

Bring back DOS 2.0

 

[GlobalNorth]

Every encryption system has its' weaknesses.

 

[lassix]

GitHub - MidnightBlueLabs/TETRA_crypto

Contribute to MidnightBlueLabs/TETRA_crypto development by creating an account on GitHub.

github.com

 

[Marawan]

anyone implemented something yet ?

 

[RFI-EMI-GUY]

TEA1 and 4 are approved for export.
90's proprietary encryption.
Not surprised at all.

Reminds me of Motorola DVP. Has a very large key variable on paper but turns out it is linear and after analysis there were only 255 (approximately) possible keys.

I'd be highly suspect of any proprietary encryption:
Motorola DVI-XL, DVP-XL
GE/Macom VGE

I would love to see an analysis on DVP-XL and VGE.

Thankfully today open encryption standards are used (AES).

Do you have a link to the report saying DVP has only 255 keys?

 

[N4DES]

Do you have a link to the report saying DVP has only 255 keys?

The basic DVP algorithm is capable of 2.36 x 10 21 different "keys" based on a key length of 32 bits.

Motorola Two-Way Encryption Products and Protocols

Free essays, homework help, flashcards, research papers, book reports, term papers, history, science, politics

studylib.net

 

[RFI-EMI-GUY]

hey, i got a shout out as a provider of sparse and/or inaccurate info in that paper

it was 1995. info on Securenet stuff was really hard to find at the time... Reference 7 ... LOL and most everyone was still on 28.8k dialup. most of the info for my article was from the various books / manuals at the local Moto shop....

Encryption Protocols

I read that twice and still trying to wrap my head around the vulnerability. I agree the silence dotting pattern is a known plaintext subject to attack. Still can't understand why the authors in 2014 could not obtain a pair of working DVP/Vulcan radios as the ebay is your friend...

 

[KevinC]

The basic DVP algorithm is capable of 2.36 x 10 21 different "keys" based on a key length of 32 bits.

Motorola Two-Way Encryption Products and Protocols

Free essays, homework help, flashcards, research papers, book reports, term papers, history, science, politics

studylib.net

That's close to 255.

 

[RFI-EMI-GUY]

That's close to 255.

1111 1111 1111 1111 1111 1111 1111 1111 = 32 bits = 4,294,967,295 decimal value

 

[Ubbe]

anyone implemented something yet ?

There's wasn't much new info available. TEA2 are still safe that perhaps are used in 75% of Tetra systems and 20% are in the clear so about 5% uses TEA1 or TEA3. They had to manipulate a TEA1 radio and system to think it had to run in cripple mode and then only use half the key length in fall back mode. Then they could brute force the key. They had to buy a Tetra basestation to do their experiments on. So no new info that can be used to monitor TEA2.

/Ubbe

 

[Marawan]

There's wasn't much new info available. TEA2 are still safe that perhaps are used in 75% of Tetra systems and 20% are in the clear so about 5% uses TEA1 or TEA3. They had to manipulate a TEA1 radio and system to think it had to run in cripple mode and then only use half the key length in fall back mode. Then they could brute force the key. They had to buy a Tetra basestation to do their experiments on. So no new info that can be used to monitor TEA2.

/Ubbe

How about tea 1
Does it require a basestaion
Can this attack implemented on offline recordings Iike what is done with Dmr and p25?

 

[RayAir]

I read that twice and still trying to wrap my head around the vulnerability. I agree the silence dotting pattern is a known plaintext subject to attack. Still can't understand why the authors in 2014 could not obtain a pair of working DVP/Vulcan radios as the ebay is your friend...

Looks like it's not letting me attach it. Let me look later for a link.

 

[Marawan]

Looks like it's not letting me attach it. Let me look later for a link.

Has anyone checked this one out?

https://l.facebook.com/l.php?u=https%3A%2F%2Fgithub.com%2Fosmocom%2Fosmo-tetra&h=AT11-xukViEfnFypvooAmMHMxz0p_ylMnQHROV4f9uNHGScZR6pBpmOSZGu5ILuLGaQs_EmylOvVglOxZRnStLigb__1ZhuUv9jBuSBeGf5pV0fS4QARPQoA71mi6Du7UKzPcIo58xc

 

[BinaryMode]

Here's the actual none tracking BS link: GitHub - osmocom/osmo-tetra: Osmocom TETRA MAC/PHY experimentation code; Mirrored from https://gitea.osmocom.org/tetra/osmo-tetra

 

[Marawan]

Here's the actual none tracking BS link: GitHub - osmocom/osmo-tetra: Osmocom TETRA MAC/PHY experimentation code; Mirrored from https://gitea.osmocom.org/tetra/osmo-tetra

So How's it
Does it work good offline?