London: German security researchers have found that freezing an Android phone can help reveal its confidential contents.
The research team at Erlangen`s Friedrich-Alexander University (FAU) froze phones for an hour as a way to get around the encryption system that protects the data on a phone by scrambling it, reports the BBC.
The attack allowed the researchers to get at contact lists, browsing histories and photos.
The team said that Android`s data scrambling system was good for end users but a "nightmare" for law enforcement and forensics workers.
Researchers Tilo Muller, Michael Spreitzenbarth and Felix Freiling put Android phone s in a freezer for an hour until the device had cooled to below -10C.
They discovered that quickly connecting and disconnecting the battery of a frozen phone forced the handset into a vulnerable mode, which helped them restart it with some custom-built software rather than its Android operating system.
The software helped them copy data on a phone that could then be analysed on a separate computer.
The German research group is now working on defences against the attack that ensures encryption keys are never put in vulnerable memory chips. Instead they are only used in