A5/1 algorithm cracked: GSM calls decoded...
By Mathieu CARBONNEAUX
At one time, we were talking about the fact that the gsm encryption algorithm was weak…
And that the army had even asked to truncate the keys to 52bits (the gsm standard defines 64bits for encryption)… to facilitate eavesdropping in case of national necessity…
The A5/1 algorithm has been protecting GSM communications with encryption since 1987. But last week, an encryption specialist named Karsten Nohl presented at a hackers’ conference the method he and 24 others used to crack this code.
The flaw only affects communications using second-generation technologies (GSM, GPRS and EDGE). Communications using 3rd generation technology (UMTS and HDSPA) or 4th generation technology (LTE) are not affected by this flaw.
It seems that the source code, which theoretically allows GSM calls to be decrypted, is available on several BitTorrent sites…
http://www.lesnumeriques.com/news_id-12170.html
http://www.clubic.com/actualite-317914-gsm-cle-chiffrement-cassee.html
http://www.echosdunet.net/dossiers/dossier_4443_le+chiffrement+gsm+casse.html