According to this news:

Researchers have found that by playing with the voltage on a device, it is possible to crack the popular RSA encryption keys. Hackers are having a field day with this research.

The article says:

“Researchers at the University of Michigan say they have uncovered a way to circumvent encryption used on many devices.

The research is the work of Valeria Bertacco, Todd Austin and Andrea Pellegrini. According to their paper, entitled ‘Fault-Based Attack of RSA Authentication’ (PDF), the trio demonstrated a way to beat the popular encryption method, which is used in media players, laptop computers, smartphones and other devices. It is also used by retailers to secure customer information online.

The researchers found that by varying the voltage on a device it was possible to get their hands on the ‘private key’ needed to beat the security feature. Using what they described as an inexpensive device specially-built for the experiment, the trio manipulated the voltage and caused the computer to make small mistakes in its communications with other clients. This ultimately revealed small pieces of the private key, which they eventually used to reconstruct the key offline.”