The recent attack on Gemalto proves how secure the SIM card actually remains, argued Giesecke & Devrient (G&D), although the German vendor did review its own security and that of its customers following last week’s report.

“Until now G&D has no knowledge that SIM card keys were stolen. Immediately after the attacks were brought to light we did, however, introduce additional measures to review the established security processes together with our customers,” said Stefan Auerbach, member of the management board and head of the mobile security business unit at G&D

Last week, a report claimed that US and UK security forces hacked Gemalto’s private network to steal crucial encryption keys for SIM cards.

“The SIM card is so secure that in the case revealed recently, even intelligence services preferred to steal the key rather than attack the SIM card,” said G&D.

G&D also said it is taking the attacks by the security services “very seriously”.

Gemalto’s latest statement (on Monday) mentioned other SIM card vendor’s possibly having their encryption keys stolen too. This appears not to include G&D.