This sounds suspiciously like modern context being retrofitted to an ancient story.. there were (and still are) much bigger problems in GSM than just the cipher in use, say for example, that phones do not authenticate the network, and the network dictates the handset's encryption mode.<p>It seems curious that the intelligence community would be so vocal in such a directly attributable manner when simpler means of interception exist, and when many other reasons could be given for reducing the key size (e.g. cost seems an obvious one, given we're talking about the 80s here), not to mention that A5/1 itself had major flaws that puts it on the level of WEP in terms of the ease with which it could (and still can) be cracked.
Relevant report by Srlabs.de: <a href="http://gsmmap.org/assets/pdfs/gsmmap.org-country_report-United_States_of_America-2013-08.pdf" rel="nofollow">http://gsmmap.org/assets/pdfs/gsmmap.org-country_report-Unit...</a><p><i>Conclusion: The GSM networks in USA implement only few of the protection measures observed in other GSM networks.</i><p>Encryption algorithms:<p><pre><code> AT&T T-Mobile
A5/0 45% 17% (ie: unencrypted)
A5/1 55% 83%</code></pre>
Snowden docs make it official: The NSA can crack 30-year-old A5/1 crypto<p><a href="http://arstechnica.com/tech-policy/2013/12/archaic-but-widely-used-crypto-cipher-allows-nsa-to-decode-most-cell-calls/" rel="nofollow">http://arstechnica.com/tech-policy/2013/12/archaic-but-widel...</a><p>Does anyone know if LTE security is that much better? I imagine that even if the ciphers are good, there are probably a ton of ways for agencies like NSA or even FBI to intercept the calls before being encrypted, even without warrants.
Ross Anderson, writing in 1994:<p>"Indeed, my spies inform me that there was a terrific row between the NATO signals agencies in the mid 1980's over whether GSM encryption should be strong or not. The Germans said it should be, as they shared a long border with the Evil Empire; but the other countries didn't feel this way. and the algorithm as now fielded is a French design."<p><a href="https://groups.google.com/forum/#!msg/uk.telecom/TkdCaytoeU4/Mroy719hdroJ" rel="nofollow">https://groups.google.com/forum/#!msg/uk.telecom/TkdCaytoeU4...</a>