The interview that is linked[0] in the footnotes of the article with the person from ETSI is absolutely wild... Some excerpts:
> kz (interviewer): How did it go about meeting those requirements, because that's the one they're saying has a backdoor in it. Was that the condition for export?
> BM (ETSI): Backdoor can mean a couple of things I think. Something like you'd stop the random number generator being random, for instance. [But] what I think was revealed [by the researchers] was that TEA1 has reduced key-entropy. So is that a backdoor? I don't know. I'm not sure it's what I would describe as a backdoor, nor would the TETRA community I think.
...
> KZ: People ... believe they're getting an 80-bit key and they're not.
> BM: Well it is an 80-bit long key. [But] if it had 80 bits of entropy, it wouldn't be exportable.
...
> kz: You're saying 25 years ago 32 bit would have been secure?
> BM: I think so. I can only assume. Because the people who designed this algorithm didn't confer with what was then EP-TETRA [ETSI Project-TETRA is the name of the working group that oversaw the development of the TETRA standard]. We were just given those algorithms. And the algorithms were designed with some assistance from some government authorities, let me put it that way.
...
> bm: That's what we now know yeah - that it did have a reduced key length.
> KZ: What do you mean we now know? SAGE created this algorithm but the Project-TETRA people did not know it had a reduced key?
> BM: That's correct. Not before it was delivered. Once the software had been delivered to them under the confidential understanding, that's the time at which they [would have known].
...
You've really got to wonder who at ETSI gave the thumbs up on doing this interview.
0 - https://www.zetter-zeroday.com/p/interview-with-the-etsi-sta...
> kz (interviewer): How did it go about meeting those requirements, because that's the one they're saying has a backdoor in it. Was that the condition for export?
> BM (ETSI): Backdoor can mean a couple of things I think. Something like you'd stop the random number generator being random, for instance. [But] what I think was revealed [by the researchers] was that TEA1 has reduced key-entropy. So is that a backdoor? I don't know. I'm not sure it's what I would describe as a backdoor, nor would the TETRA community I think.
...
> KZ: People ... believe they're getting an 80-bit key and they're not.
> BM: Well it is an 80-bit long key. [But] if it had 80 bits of entropy, it wouldn't be exportable.
...
> kz: You're saying 25 years ago 32 bit would have been secure?
> BM: I think so. I can only assume. Because the people who designed this algorithm didn't confer with what was then EP-TETRA [ETSI Project-TETRA is the name of the working group that oversaw the development of the TETRA standard]. We were just given those algorithms. And the algorithms were designed with some assistance from some government authorities, let me put it that way.
...
> bm: That's what we now know yeah - that it did have a reduced key length.
> KZ: What do you mean we now know? SAGE created this algorithm but the Project-TETRA people did not know it had a reduced key?
> BM: That's correct. Not before it was delivered. Once the software had been delivered to them under the confidential understanding, that's the time at which they [would have known].
...
You've really got to wonder who at ETSI gave the thumbs up on doing this interview.
0 - https://www.zetter-zeroday.com/p/interview-with-the-etsi-sta...