Encrypted radio system had unsuspected backdoor

[Swamp Thing]

A secret encryption cipher baked into radio systems used by critical infrastructure workers, police, and others around the world is finally seeing sunlight. Researchers say it isn’t pretty.

https://www.wired.com/story/tetra-radio-encryption-backdoor/

 

[Klystron]

In a brief email, NCSC spokesperson Miral Scheffer called TETRA “a crucial foundation for mission-critical communication in the Netherlands and around the world” and emphasized the need for such communications to always be reliable and secure, “especially during crisis situations.”

A worthwhile yet elusive goal. The article also raises the question what constitutes, depending on application, the useful field life of an encryption strategy. Time stamp exploitations have been used to spoof radar for decades. Not surprised that encrypted radio casting suffers similar exploitation.

 

[Baluncore]

Every commercial encryption system, must be expected to have a well hidden trapdoor, for use by the security services. Always use a system with that in mind.

Traditional cryptanalysis will always be slow and expensive. If you have not yet found the trapdoor, you will have to capture a copy of the key, bribe, or entrap an operator. Every man has his price. Those techniques are collectively known as "practical cryptanalysis".

But now it’s finally getting a public airing thanks to a small group of researchers in the Netherlands who got their hands on its viscera and found serious flaws, including a deliberate backdoor.

That a trapdoor has now been identified, reduces the price, or spells the end of the encryption product, but only to users requiring higher security.

When a third party cracks a widely used encryption system, they must decide between either national security or publicity.

My guess is that the research was funded by a competitive product manufacturer with a smaller market share, and approved for publication by their national security agency. That will normally only happen when a common enemy finds and begins to exploit the weakness. Obviously, 25 years was too long an exposure to remain secure.