A Smartphone as a Secure Building Access Key
Using the smartphone as a door key is not a new capability. With electronic locks on the home network, a remote device (such as a phone) with security access can send a signal to ask for the door to be unlocked, without coming into contact with that door. What has been missing however, is the ability to do so securely. To ensure that anyone listening in on the cell network, isn't able to copy and reproduce the signal to order the front door of the house (or any other doors, internal or external) to unlock themselves, providing entry to unauthorised visitors.
A research effort by Prof. Ahmad-Reza Sadeghi of the Fraunhofer Institute for
Secure Information Technology, has provided one potential solution for this
problem. At this years CeBIT trade fair in Hannover, Germany, the research
team lead by the professor will be
ShareKey works using the Near Field Communication (NFC) transmission standard, which allows data to be exchanged wirelessly over short ranges of up to a few centimetres.To open a door, all you need to do is hold your mobile phone close to the lock, says Dmitrienko. NFC interface and door locks only operate within a narrow bandwidth and have limited computing power.
The signal thus does not send over any great distance, and you would have to be present within just a few feet of the phone in order to intercept the signal in the first place. Intercepting it however, will do you little good. The electronic keys on the smart phone are encrypted, and as part of the ShareKey system, the encryption used changes every time. Both the phone and the locks are updated each time they are used, so no two signals will be the same.
Different users have different access accounts with optionally different access rights, and of course, a unique encrypted key for each user. Such then makes it additionally feasible to tell which individual entered the house and when, from the house's central computer system.
Alongside front doors and parcel or locker compartments, the research scientist also suggests that the technology could potentially be applied to help administer keys in hotels or as part of car-sharing schemes. The trend towards a shareconomy will benefit the further development of this technology, concludes Dmitrienko.