Researchers at the Horst Görtz Institute for IT-Security at Germany’s Ruhr University Bochum have cracked the A5-GMR-1 and A5-GMR-2 encryption algorithms of the European Telecommunications Standards Institute. The ETSI algorithms, which are used for satellite telephones, were breached within an hour.
The research team started by analysing firmware updates provided by satellite phone companies for their customers. One of the security standards was noted to be similar to a GSM code that had previously been broken. The researchers adopted the GSM cracking method and applied it to a satellite phone conversation.
Ralf Hund, from the Chair for System Security at Ruhr University Bochum, said “Our results show that the use of satellite phones harbours dangers and the current encryption algorithms are not sufficient.”
The researchers are currently able to decrypt non-voice communications but have not yet reverse-engineered the speech codec to eavesdrop on a conversation.