Scientists have found a way to circumvent the encryption used to protect a smartcard used to restrict access to buildings and to process public transit system payments.
A team of German scientists have demonstrated a hack that lets them make a perfect clone of the kind of magnetic security card used to give access to workers in corporate or government buildings -- including NASA -- and as a daily ticket replacement on buses and subways. The same team broke a previous version of contactless-ID cards from Mifare in 2008. This prompted the company to upgrade its security to create a card able to be programmed only once and which contained a unique identifying number that could be checked against the programmed content on the card for extra security.
The new hack is carried out using a side channel attack, which bypasses the defensive features intended to prevent attacks on the card. To achieve this, the researchers made repeated measurements of electricity consumption during encryption and decryption. This can be determined by measuring the magnetic field close to the card.