Security researchers from Tel Aviv University, Technion and The University of Adelaide have devised an attack to steal cryptographic keys used to protect Bitcoin wallets, Apple Pay accounts, and other highly sensitive services. The hack requires an attacker to have physical control of, or, at least a probe or cable in proximity to, a vulnerable mobile device as long as it performed enough tasks to measure a few thousand of ECDSA signatures. The researchers also experimented their exploit on a Sony-Ericsson Xperia X10 Phone running Android and said they believe such an attack is feasible.
Source: https://thehackernews.com/2016/03/encryption-keys-android.html