Information Security Stack Exchange is a question and answer site for information security professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

It appears that GSM is like any other technology, and is only as secure as its implementation.

What implementations are known to be secure or insecure due to a fault on the implementor's side, or due to the Moore's law and the ability to easily crack the underlying encryption?

share|improve this question
Are you mainly concerned with voice confidentiality? Are there other issues you are interested in such as voice service availability, integrity of data on the handset, confidentiality of the data on the handset, etc – this.josh Jun 22 '11 at 6:58
@this.josh - I'm mostly interested in data-in-transport, not data-at-rest. I'm sure data at rest will be a natural followup; but should be easily discoverable. – LamonteCristo Jun 23 '11 at 16:47
up vote 3 down vote accepted

The situation is worse than that. Various political forces led to GSM being weaker than it should have been, and as is often the case with proprietary technologies, the security engineering of GSM was flawed. Both the A5/1 and A5/2 stream ciphers have been broken, and there are weaknesses in the latest, KASUMI (aka A5/3), despite indications that they knew better than that. So it seems that any compliant implementation puts users at risk. This much is clear from GSM - Wikipedia

share|improve this answer
Great information, but I don't think it really answers the question. Do you consider no implementation of GSM to be relatively more secure than any other? You could even be more specific by considering only base stations, or base stations that are only UMTS versus combination GSM (2G) and UMTS. – this.josh Jun 20 '11 at 6:05
this.josh - Indeed. If I knew enough to compare implementations, I'd be happy to answer, but this is what I have to offer, and it shows the limits of even good implementations. – nealmcb Jun 22 '11 at 4:33

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.